diff --git a/backend/backend.go b/backend/backend.go
index 1ce72784..85a8ee1d 100644
--- a/backend/backend.go
+++ b/backend/backend.go
@@ -9,7 +9,7 @@ import (
 
 // ErrInvalidCredentials is returned by Backend.Login when a username or a
 // password is incorrect.
-var ErrInvalidCredentials = errors.New("Invalid credentials")
+var ErrInvalidCredentials = errors.New("invalid credentials")
 
 // Backend is an IMAP server backend. A backend operation always deals with
 // users.
diff --git a/backend/backendutil/backendutil_test.go b/backend/backendutil/backendutil_test.go
index 79633308..c8c46476 100644
--- a/backend/backendutil/backendutil_test.go
+++ b/backend/backendutil/backendutil_test.go
@@ -11,7 +11,7 @@ const testHeaderString = "Content-Type: multipart/mixed; boundary=message-bounda
 	"Date: Sat, 19 Jun 2016 12:00:00 +0900\r\n" +
 	"From: Mitsuha Miyamizu <mitsuha.miyamizu@example.org>\r\n" +
 	"Reply-To: Mitsuha Miyamizu <mitsuha.miyamizu+replyto@example.org>\r\n" +
-	"Message-Id: 42@example.org\r\n" +
+	"Message-ID: 42@example.org\r\n" +
 	"Subject: Your Name.\r\n" +
 	"To: Taki Tachibana <taki.tachibana@example.org>\r\n" +
 	"\r\n"
@@ -28,7 +28,7 @@ const testHeaderNoFromToString = "Content-Type: multipart/mixed; boundary=messag
 	"Date: Sat, 18 Jun 2016 12:00:00 +0900\r\n" +
 	"Date: Sat, 19 Jun 2016 12:00:00 +0900\r\n" +
 	"Reply-To: Mitsuha Miyamizu <mitsuha.miyamizu+replyto@example.org>\r\n" +
-	"Message-Id: 42@example.org\r\n" +
+	"Message-ID: 42@example.org\r\n" +
 	"Subject: Your Name.\r\n" +
 	"\r\n"
 
diff --git a/backend/backendutil/body_test.go b/backend/backendutil/body_test.go
index 252a0845..9acd12bc 100644
--- a/backend/backendutil/body_test.go
+++ b/backend/backendutil/body_test.go
@@ -144,7 +144,7 @@ func TestFetchBodySection_NonMultipart(t *testing.T) {
 	testMsgHdr := "From: Mitsuha Miyamizu <mitsuha.miyamizu@example.org>\r\n" +
 		"To: Taki Tachibana <taki.tachibana@example.org>\r\n" +
 		"Subject: Your Name.\r\n" +
-		"Message-Id: 42@example.org\r\n" +
+		"Message-ID: 42@example.org\r\n" +
 		"\r\n"
 	testMsgBody := "That's not multipart message. Thought it should be possible to get this text using BODY[1]."
 	testMsg := testMsgHdr + testMsgBody
diff --git a/backend/backendutil/bodystructure.go b/backend/backendutil/bodystructure.go
index 101f16f3..2cbf700a 100644
--- a/backend/backendutil/bodystructure.go
+++ b/backend/backendutil/bodystructure.go
@@ -26,7 +26,7 @@ func FetchBodyStructure(header textproto.Header, body io.Reader, extended bool)
 		bs.MIMESubType = "plain"
 	}
 
-	bs.Id = header.Get("Content-Id")
+	bs.ID = header.Get("Content-ID")
 	bs.Description = header.Get("Content-Description")
 	bs.Encoding = header.Get("Content-Transfer-Encoding")
 	// TODO: bs.Size
diff --git a/backend/backendutil/envelope.go b/backend/backendutil/envelope.go
index 584620d1..f5e1f905 100644
--- a/backend/backendutil/envelope.go
+++ b/backend/backendutil/envelope.go
@@ -52,7 +52,7 @@ func FetchEnvelope(h textproto.Header) (*imap.Envelope, error) {
 	env.Cc, _ = headerAddressList(h.Get("Cc"))
 	env.Bcc, _ = headerAddressList(h.Get("Bcc"))
 	env.InReplyTo = h.Get("In-Reply-To")
-	env.MessageId = h.Get("Message-Id")
+	env.MessageID = h.Get("Message-ID")
 
 	return env, nil
 }
diff --git a/backend/backendutil/envelope_test.go b/backend/backendutil/envelope_test.go
index a708c060..c62cb3ad 100644
--- a/backend/backendutil/envelope_test.go
+++ b/backend/backendutil/envelope_test.go
@@ -20,7 +20,7 @@ var testEnvelope = &imap.Envelope{
 	Cc:        []*imap.Address{},
 	Bcc:       []*imap.Address{},
 	InReplyTo: "",
-	MessageId: "42@example.org",
+	MessageID: "42@example.org",
 }
 
 func TestFetchEnvelope(t *testing.T) {
diff --git a/backend/backendutil/flags_test.go b/backend/backendutil/flags_test.go
index 26c5d9d3..6c27f7f2 100644
--- a/backend/backendutil/flags_test.go
+++ b/backend/backendutil/flags_test.go
@@ -37,7 +37,7 @@ var updateFlagsTests = []struct {
 func TestUpdateFlags(t *testing.T) {
 	current := []string{"a", "b", "c"}
 	for _, test := range updateFlagsTests {
-		got := UpdateFlags(current[:], test.op, test.flags)
+		got := UpdateFlags(current, test.op, test.flags)
 
 		if !reflect.DeepEqual(got, test.res) {
 			t.Errorf("Expected result to be \n%v\n but got \n%v", test.res, got)
diff --git a/backend/backendutil/search.go b/backend/backendutil/search.go
index 8aaa62b0..07ec12fe 100644
--- a/backend/backendutil/search.go
+++ b/backend/backendutil/search.go
@@ -136,8 +136,8 @@ func Match(e *message.Entity, seqNum, uid uint32, date time.Time, flags []string
 		}
 	}
 
-	if c.SeqNum != nil || c.Uid != nil {
-		if !matchSeqNumAndUid(seqNum, uid, c) {
+	if c.SeqNum != nil || c.UID != nil {
+		if !matchSeqNumAndUID(seqNum, uid, c) {
 			return false, nil
 		}
 	}
@@ -183,11 +183,11 @@ func matchFlags(flags []string, c *imap.SearchCriteria) bool {
 	return true
 }
 
-func matchSeqNumAndUid(seqNum uint32, uid uint32, c *imap.SearchCriteria) bool {
+func matchSeqNumAndUID(seqNum uint32, uid uint32, c *imap.SearchCriteria) bool {
 	if c.SeqNum != nil && !c.SeqNum.Contains(seqNum) {
 		return false
 	}
-	if c.Uid != nil && !c.Uid.Contains(uid) {
+	if c.UID != nil && !c.UID.Contains(uid) {
 		return false
 	}
 	return true
diff --git a/backend/backendutil/search_test.go b/backend/backendutil/search_test.go
index 15639b44..c0dae4e0 100644
--- a/backend/backendutil/search_test.go
+++ b/backend/backendutil/search_test.go
@@ -65,19 +65,19 @@ var matchTests = []struct {
 	},
 	{
 		criteria: &imap.SearchCriteria{
-			Header: textproto.MIMEHeader{"Message-Id": {"42@example.org"}},
+			Header: textproto.MIMEHeader{"Message-ID": {"42@example.org"}},
 		},
 		res: true,
 	},
 	{
 		criteria: &imap.SearchCriteria{
-			Header: textproto.MIMEHeader{"Message-Id": {"43@example.org"}},
+			Header: textproto.MIMEHeader{"Message-ID": {"43@example.org"}},
 		},
 		res: false,
 	},
 	{
 		criteria: &imap.SearchCriteria{
-			Header: textproto.MIMEHeader{"Message-Id": {""}},
+			Header: textproto.MIMEHeader{"Message-ID": {""}},
 		},
 		res: true,
 	},
@@ -160,7 +160,7 @@ var matchTests = []struct {
 		criteria: &imap.SearchCriteria{
 			Or: [][2]*imap.SearchCriteria{{
 				{
-					Uid: new(imap.SeqSet),
+					UID: new(imap.SeqSet),
 					Not: []*imap.SearchCriteria{{SeqNum: new(imap.SeqSet)}},
 				},
 				{
@@ -176,7 +176,7 @@ var matchTests = []struct {
 		criteria: &imap.SearchCriteria{
 			Or: [][2]*imap.SearchCriteria{{
 				{
-					Uid: &imap.SeqSet{Set: []imap.Seq{{69, 69}}},
+					UID: &imap.SeqSet{Set: []imap.Seq{{69, 69}}},
 					Not: []*imap.SearchCriteria{{SeqNum: new(imap.SeqSet)}},
 				},
 				{
@@ -192,9 +192,9 @@ var matchTests = []struct {
 		criteria: &imap.SearchCriteria{
 			Or: [][2]*imap.SearchCriteria{{
 				{
-					Uid: &imap.SeqSet{Set: []imap.Seq{{69, 69}}},
+					UID: &imap.SeqSet{Set: []imap.Seq{{69, 69}}},
 					Not: []*imap.SearchCriteria{{
-						SeqNum: &imap.SeqSet{Set: []imap.Seq{imap.Seq{42, 42}}},
+						SeqNum: &imap.SeqSet{Set: []imap.Seq{{42, 42}}},
 					}},
 				},
 				{
@@ -210,7 +210,7 @@ var matchTests = []struct {
 		criteria: &imap.SearchCriteria{
 			Or: [][2]*imap.SearchCriteria{{
 				{
-					Uid: &imap.SeqSet{Set: []imap.Seq{{69, 69}}},
+					UID: &imap.SeqSet{Set: []imap.Seq{{69, 69}}},
 					Not: []*imap.SearchCriteria{{
 						SeqNum: &imap.SeqSet{Set: []imap.Seq{{42, 42}}},
 					}},
diff --git a/backend/memory/backend.go b/backend/memory/backend.go
index 25c65ab8..d4981cc3 100644
--- a/backend/memory/backend.go
+++ b/backend/memory/backend.go
@@ -19,7 +19,7 @@ func (be *Backend) Login(_ *imap.ConnInfo, username, password string) (backend.U
 		return user, nil
 	}
 
-	return nil, errors.New("Bad username or password")
+	return nil, errors.New("bad username or password")
 }
 
 func New() *Backend {
@@ -40,7 +40,7 @@ func New() *Backend {
 			user: user,
 			Messages: []*Message{
 				{
-					Uid:   6,
+					UID:   6,
 					Date:  time.Now(),
 					Flags: []string{"\\Seen"},
 					Size:  uint32(len(body)),
diff --git a/backend/memory/mailbox.go b/backend/memory/mailbox.go
index 2d0fa9f0..8ffd4ad8 100644
--- a/backend/memory/mailbox.go
+++ b/backend/memory/mailbox.go
@@ -34,8 +34,8 @@ func (mbox *Mailbox) Info() (*imap.MailboxInfo, error) {
 func (mbox *Mailbox) uidNext() uint32 {
 	var uid uint32
 	for _, msg := range mbox.Messages {
-		if msg.Uid > uid {
-			uid = msg.Uid
+		if msg.UID > uid {
+			uid = msg.UID
 		}
 	}
 	uid++
@@ -52,7 +52,7 @@ func (mbox *Mailbox) flags() []string {
 		}
 	}
 
-	var flags []string
+	flags := make([]string, 0, len(flagsMap))
 	for f := range flagsMap {
 		flags = append(flags, f)
 	}
@@ -88,10 +88,10 @@ func (mbox *Mailbox) Status(items []imap.StatusItem) (*imap.MailboxStatus, error
 		switch name {
 		case imap.StatusMessages:
 			status.Messages = uint32(len(mbox.Messages))
-		case imap.StatusUidNext:
-			status.UidNext = mbox.uidNext()
-		case imap.StatusUidValidity:
-			status.UidValidity = 1
+		case imap.StatusUIDNext:
+			status.UIDNext = mbox.uidNext()
+		case imap.StatusUIDValidity:
+			status.UIDValidity = 1
 		case imap.StatusRecent:
 			status.Recent = 0 // TODO
 		case imap.StatusUnseen:
@@ -119,7 +119,7 @@ func (mbox *Mailbox) ListMessages(uid bool, seqSet *imap.SeqSet, items []imap.Fe
 
 		var id uint32
 		if uid {
-			id = msg.Uid
+			id = msg.UID
 		} else {
 			id = seqNum
 		}
@@ -139,7 +139,7 @@ func (mbox *Mailbox) ListMessages(uid bool, seqSet *imap.SeqSet, items []imap.Fe
 }
 
 func (mbox *Mailbox) SearchMessages(uid bool, criteria *imap.SearchCriteria) ([]uint32, error) {
-	var ids []uint32
+	ids := make([]uint32, 0, len(mbox.Messages))
 	for i, msg := range mbox.Messages {
 		seqNum := uint32(i + 1)
 
@@ -150,7 +150,7 @@ func (mbox *Mailbox) SearchMessages(uid bool, criteria *imap.SearchCriteria) ([]
 
 		var id uint32
 		if uid {
-			id = msg.Uid
+			id = msg.UID
 		} else {
 			id = seqNum
 		}
@@ -170,7 +170,7 @@ func (mbox *Mailbox) CreateMessage(flags []string, date time.Time, body imap.Lit
 	}
 
 	mbox.Messages = append(mbox.Messages, &Message{
-		Uid:   mbox.uidNext(),
+		UID:   mbox.uidNext(),
 		Date:  date,
 		Size:  uint32(len(b)),
 		Flags: flags,
@@ -183,7 +183,7 @@ func (mbox *Mailbox) UpdateMessagesFlags(uid bool, seqset *imap.SeqSet, op imap.
 	for i, msg := range mbox.Messages {
 		var id uint32
 		if uid {
-			id = msg.Uid
+			id = msg.UID
 		} else {
 			id = uint32(i + 1)
 		}
@@ -206,7 +206,7 @@ func (mbox *Mailbox) CopyMessages(uid bool, seqset *imap.SeqSet, destName string
 	for i, msg := range mbox.Messages {
 		var id uint32
 		if uid {
-			id = msg.Uid
+			id = msg.UID
 		} else {
 			id = uint32(i + 1)
 		}
@@ -215,7 +215,7 @@ func (mbox *Mailbox) CopyMessages(uid bool, seqset *imap.SeqSet, destName string
 		}
 
 		msgCopy := *msg
-		msgCopy.Uid = dest.uidNext()
+		msgCopy.UID = dest.uidNext()
 		dest.Messages = append(dest.Messages, &msgCopy)
 	}
 
diff --git a/backend/memory/message.go b/backend/memory/message.go
index 58290589..02e9d8a2 100644
--- a/backend/memory/message.go
+++ b/backend/memory/message.go
@@ -13,7 +13,7 @@ import (
 )
 
 type Message struct {
-	Uid   uint32
+	UID   uint32
 	Date  time.Time
 	Size  uint32
 	Flags []string
@@ -46,8 +46,8 @@ func (m *Message) Fetch(seqNum uint32, items []imap.FetchItem) (*imap.Message, e
 			fetched.InternalDate = m.Date
 		case imap.FetchRFC822Size:
 			fetched.Size = m.Size
-		case imap.FetchUid:
-			fetched.Uid = m.Uid
+		case imap.FetchUID:
+			fetched.UID = m.UID
 		default:
 			section, err := imap.ParseBodySectionName(item)
 			if err != nil {
@@ -70,5 +70,5 @@ func (m *Message) Fetch(seqNum uint32, items []imap.FetchItem) (*imap.Message, e
 
 func (m *Message) Match(seqNum uint32, c *imap.SearchCriteria) (bool, error) {
 	e, _ := m.entity()
-	return backendutil.Match(e, seqNum, m.Uid, m.Date, m.Flags, c)
+	return backendutil.Match(e, seqNum, m.UID, m.Date, m.Flags, c)
 }
diff --git a/backend/memory/user.go b/backend/memory/user.go
index 5a4d3761..2eef0f42 100644
--- a/backend/memory/user.go
+++ b/backend/memory/user.go
@@ -30,14 +30,14 @@ func (u *User) ListMailboxes(subscribed bool) (mailboxes []backend.Mailbox, err
 func (u *User) GetMailbox(name string) (mailbox backend.Mailbox, err error) {
 	mailbox, ok := u.mailboxes[name]
 	if !ok {
-		err = errors.New("No such mailbox")
+		err = errors.New("no such mailbox")
 	}
 	return
 }
 
 func (u *User) CreateMailbox(name string) error {
 	if _, ok := u.mailboxes[name]; ok {
-		return errors.New("Mailbox already exists")
+		return errors.New("mailbox already exists")
 	}
 
 	u.mailboxes[name] = &Mailbox{name: name, user: u}
@@ -46,10 +46,10 @@ func (u *User) CreateMailbox(name string) error {
 
 func (u *User) DeleteMailbox(name string) error {
 	if name == "INBOX" {
-		return errors.New("Cannot delete INBOX")
+		return errors.New("cannot delete INBOX")
 	}
 	if _, ok := u.mailboxes[name]; !ok {
-		return errors.New("No such mailbox")
+		return errors.New("no such mailbox")
 	}
 
 	delete(u.mailboxes, name)
@@ -59,7 +59,7 @@ func (u *User) DeleteMailbox(name string) error {
 func (u *User) RenameMailbox(existingName, newName string) error {
 	mbox, ok := u.mailboxes[existingName]
 	if !ok {
-		return errors.New("No such mailbox")
+		return errors.New("no such mailbox")
 	}
 
 	u.mailboxes[newName] = &Mailbox{
diff --git a/backend/updates.go b/backend/updates.go
index 1c87573e..ba10f884 100644
--- a/backend/updates.go
+++ b/backend/updates.go
@@ -72,14 +72,14 @@ type ExpungeUpdate struct {
 	SeqNum uint32
 }
 
-// BackendUpdater is a Backend that implements Updater is able to send
+// Updater is a Backend that implements Updater is able to send
 // unilateral backend updates. Backends not implementing this interface don't
 // correctly send unilateral updates, for instance if a user logs in from two
 // connections and deletes a message from one of them, the over is not aware
 // that such a mesage has been deleted. More importantly, backends implementing
 // Updater can notify the user for external updates such as new message
 // notifications.
-type BackendUpdater interface {
+type Updater interface {
 	// Updates returns a set of channels where updates are sent to.
 	Updates() <-chan Update
 }
diff --git a/backend/user.go b/backend/user.go
index afcd0142..2b254589 100644
--- a/backend/user.go
+++ b/backend/user.go
@@ -6,10 +6,10 @@ var (
 	// ErrNoSuchMailbox is returned by User.GetMailbox, User.DeleteMailbox and
 	// User.RenameMailbox when retrieving, deleting or renaming a mailbox that
 	// doesn't exist.
-	ErrNoSuchMailbox = errors.New("No such mailbox")
+	ErrNoSuchMailbox = errors.New("no such mailbox")
 	// ErrMailboxAlreadyExists is returned by User.CreateMailbox and
 	// User.RenameMailbox when creating or renaming mailbox that already exists.
-	ErrMailboxAlreadyExists = errors.New("Mailbox already exists")
+	ErrMailboxAlreadyExists = errors.New("mailbox already exists")
 )
 
 // User represents a user in the mail storage system. A user operation always
diff --git a/client/client.go b/client/client.go
index 8e53579c..46dce107 100644
--- a/client/client.go
+++ b/client/client.go
@@ -218,7 +218,7 @@ func (c *Client) execute(cmdr imap.Commander, h responses.Handler) (*imap.Status
 	c.registerHandler(responses.HandlerFunc(func(resp imap.Resp) error {
 		select {
 		case <-unregister:
-			// If an error occured while sending the command, abort
+			// If an error occurred while sending the command, abort
 			return errUnregisterHandler
 		default:
 		}
@@ -566,7 +566,6 @@ func (c *Client) SetDebug(w io.Writer) {
 	if err != nil {
 		log.Println("SetDebug:", err)
 	}
-
 }
 
 // New creates a new client from an existing connection.
diff --git a/client/cmd_any.go b/client/cmd_any.go
index 3268052b..54e65f0a 100644
--- a/client/cmd_any.go
+++ b/client/cmd_any.go
@@ -9,7 +9,7 @@ import (
 
 // ErrAlreadyLoggedOut is returned if Logout is called when the client is
 // already logged out.
-var ErrAlreadyLoggedOut = errors.New("Already logged out")
+var ErrAlreadyLoggedOut = errors.New("already logged out")
 
 // Capability requests a listing of capabilities that the server supports.
 // Capabilities are often returned by the server with the greeting or with the
diff --git a/client/cmd_auth.go b/client/cmd_auth.go
index 62e4d018..554c377c 100644
--- a/client/cmd_auth.go
+++ b/client/cmd_auth.go
@@ -11,7 +11,7 @@ import (
 
 // ErrNotLoggedIn is returned if a function that requires the client to be
 // logged in is called then the client isn't.
-var ErrNotLoggedIn = errors.New("Not logged in")
+var ErrNotLoggedIn = errors.New("not logged in")
 
 func (c *Client) ensureAuthenticated() error {
 	state := c.State()
diff --git a/client/cmd_auth_test.go b/client/cmd_auth_test.go
index dd9953df..f396bb3d 100644
--- a/client/cmd_auth_test.go
+++ b/client/cmd_auth_test.go
@@ -50,8 +50,8 @@ func TestClient_Select(t *testing.T) {
 		UnseenSeqNum:   12,
 		Messages:       172,
 		Recent:         1,
-		UidNext:        4392,
-		UidValidity:    3857529045,
+		UIDNext:        4392,
+		UIDValidity:    3857529045,
 	}
 	mbox.Items = nil
 	if !reflect.DeepEqual(mbox, want) {
diff --git a/client/cmd_noauth.go b/client/cmd_noauth.go
index f9b34d3e..c8e5c237 100644
--- a/client/cmd_noauth.go
+++ b/client/cmd_noauth.go
@@ -14,14 +14,14 @@ import (
 var (
 	// ErrAlreadyLoggedIn is returned if Login or Authenticate is called when the
 	// client is already logged in.
-	ErrAlreadyLoggedIn = errors.New("Already logged in")
+	ErrAlreadyLoggedIn = errors.New("already logged in")
 	// ErrTLSAlreadyEnabled is returned if StartTLS is called when TLS is already
 	// enabled.
 	ErrTLSAlreadyEnabled = errors.New("TLS is already enabled")
 	// ErrLoginDisabled is returned if Login or Authenticate is called when the
 	// server has disabled authentication. Most of the time, calling enabling TLS
 	// solves the problem.
-	ErrLoginDisabled = errors.New("Login is disabled in current state")
+	ErrLoginDisabled = errors.New("login is disabled in current state")
 )
 
 // SupportStartTLS checks if the server supports STARTTLS.
diff --git a/client/cmd_selected.go b/client/cmd_selected.go
index 0607247e..a41439f6 100644
--- a/client/cmd_selected.go
+++ b/client/cmd_selected.go
@@ -10,7 +10,7 @@ import (
 
 // ErrNoMailboxSelected is returned if a command that requires a mailbox to be
 // selected is called when there isn't.
-var ErrNoMailboxSelected = errors.New("No mailbox selected")
+var ErrNoMailboxSelected = errors.New("no mailbox selected")
 
 // Check requests a checkpoint of the currently selected mailbox. A checkpoint
 // refers to any implementation-dependent housekeeping associated with the
@@ -93,7 +93,7 @@ func (c *Client) executeSearch(uid bool, criteria *imap.SearchCriteria, charset
 		Criteria: criteria,
 	}
 	if uid {
-		cmd = &commands.Uid{Cmd: cmd}
+		cmd = &commands.UID{Cmd: cmd}
 	}
 
 	res := new(responses.Search)
@@ -127,9 +127,9 @@ func (c *Client) Search(criteria *imap.SearchCriteria) (seqNums []uint32, err er
 	return c.search(false, criteria)
 }
 
-// UidSearch is identical to Search, but UIDs are returned instead of message
+// UIDSearch is identical to Search, but UIDs are returned instead of message
 // sequence numbers.
-func (c *Client) UidSearch(criteria *imap.SearchCriteria) (uids []uint32, err error) {
+func (c *Client) UIDSearch(criteria *imap.SearchCriteria) (uids []uint32, err error) {
 	return c.search(true, criteria)
 }
 
@@ -145,7 +145,7 @@ func (c *Client) fetch(uid bool, seqset *imap.SeqSet, items []imap.FetchItem, ch
 		Items:  items,
 	}
 	if uid {
-		cmd = &commands.Uid{Cmd: cmd}
+		cmd = &commands.UID{Cmd: cmd}
 	}
 
 	res := &responses.Fetch{Messages: ch}
@@ -163,9 +163,9 @@ func (c *Client) Fetch(seqset *imap.SeqSet, items []imap.FetchItem, ch chan *ima
 	return c.fetch(false, seqset, items, ch)
 }
 
-// UidFetch is identical to Fetch, but seqset is interpreted as containing
+// UIDFetch is identical to Fetch, but seqset is interpreted as containing
 // unique identifiers instead of message sequence numbers.
-func (c *Client) UidFetch(seqset *imap.SeqSet, items []imap.FetchItem, ch chan *imap.Message) error {
+func (c *Client) UIDFetch(seqset *imap.SeqSet, items []imap.FetchItem, ch chan *imap.Message) error {
 	return c.fetch(true, seqset, items, ch)
 }
 
@@ -198,7 +198,7 @@ func (c *Client) store(uid bool, seqset *imap.SeqSet, item imap.StoreItem, value
 		Value:  value,
 	}
 	if uid {
-		cmd = &commands.Uid{Cmd: cmd}
+		cmd = &commands.UID{Cmd: cmd}
 	}
 
 	var h responses.Handler
@@ -221,9 +221,9 @@ func (c *Client) Store(seqset *imap.SeqSet, item imap.StoreItem, value interface
 	return c.store(false, seqset, item, value, ch)
 }
 
-// UidStore is identical to Store, but seqset is interpreted as containing
+// UIDStore is identical to Store, but seqset is interpreted as containing
 // unique identifiers instead of message sequence numbers.
-func (c *Client) UidStore(seqset *imap.SeqSet, item imap.StoreItem, value interface{}, ch chan *imap.Message) error {
+func (c *Client) UIDStore(seqset *imap.SeqSet, item imap.StoreItem, value interface{}, ch chan *imap.Message) error {
 	return c.store(true, seqset, item, value, ch)
 }
 
@@ -237,7 +237,7 @@ func (c *Client) copy(uid bool, seqset *imap.SeqSet, dest string) error {
 		Mailbox: dest,
 	}
 	if uid {
-		cmd = &commands.Uid{Cmd: cmd}
+		cmd = &commands.UID{Cmd: cmd}
 	}
 
 	status, err := c.execute(cmd, nil)
@@ -253,8 +253,8 @@ func (c *Client) Copy(seqset *imap.SeqSet, dest string) error {
 	return c.copy(false, seqset, dest)
 }
 
-// UidCopy is identical to Copy, but seqset is interpreted as containing unique
+// UIDCopy is identical to Copy, but seqset is interpreted as containing unique
 // identifiers instead of message sequence numbers.
-func (c *Client) UidCopy(seqset *imap.SeqSet, dest string) error {
+func (c *Client) UIDCopy(seqset *imap.SeqSet, dest string) error {
 	return c.copy(true, seqset, dest)
 }
diff --git a/client/cmd_selected_test.go b/client/cmd_selected_test.go
index 47c1f135..ade9f00c 100644
--- a/client/cmd_selected_test.go
+++ b/client/cmd_selected_test.go
@@ -158,7 +158,7 @@ func TestClient_Search_Uid(t *testing.T) {
 	var results []uint32
 	go func() {
 		var err error
-		results, err = c.UidSearch(criteria)
+		results, err = c.UIDSearch(criteria)
 		done <- err
 	}()
 
@@ -188,7 +188,7 @@ func TestClient_Fetch(t *testing.T) {
 	setClientState(c, imap.SelectedState, nil)
 
 	seqset, _ := imap.ParseSeqSet("2:3")
-	fields := []imap.FetchItem{imap.FetchUid, imap.FetchItem("BODY[]")}
+	fields := []imap.FetchItem{imap.FetchUID, imap.FetchItem("BODY[]")}
 
 	done := make(chan error, 1)
 	messages := make(chan *imap.Message, 2)
@@ -221,8 +221,8 @@ func TestClient_Fetch(t *testing.T) {
 	if msg.SeqNum != 2 {
 		t.Errorf("First message has bad sequence number: %v", msg.SeqNum)
 	}
-	if msg.Uid != 42 {
-		t.Errorf("First message has bad UID: %v", msg.Uid)
+	if msg.UID != 42 {
+		t.Errorf("First message has bad UID: %v", msg.UID)
 	}
 	if body, _ := ioutil.ReadAll(msg.GetBody(section)); string(body) != "I love potatoes." {
 		t.Errorf("First message has bad body: %q", body)
@@ -232,8 +232,8 @@ func TestClient_Fetch(t *testing.T) {
 	if msg.SeqNum != 3 {
 		t.Errorf("First message has bad sequence number: %v", msg.SeqNum)
 	}
-	if msg.Uid != 28 {
-		t.Errorf("Second message has bad UID: %v", msg.Uid)
+	if msg.UID != 28 {
+		t.Errorf("Second message has bad UID: %v", msg.UID)
 	}
 	if body, _ := ioutil.ReadAll(msg.GetBody(section)); string(body) != "Hello World!" {
 		t.Errorf("Second message has bad body: %q", body)
@@ -247,7 +247,7 @@ func TestClient_Fetch_ClosedState(t *testing.T) {
 	setClientState(c, imap.AuthenticatedState, nil)
 
 	seqset, _ := imap.ParseSeqSet("2:3")
-	fields := []imap.FetchItem{imap.FetchUid, imap.FetchItem("BODY[]")}
+	fields := []imap.FetchItem{imap.FetchUID, imap.FetchItem("BODY[]")}
 
 	done := make(chan error, 1)
 	messages := make(chan *imap.Message, 2)
@@ -351,7 +351,7 @@ func TestClient_Fetch_Uid(t *testing.T) {
 	done := make(chan error, 1)
 	messages := make(chan *imap.Message, 1)
 	go func() {
-		done <- c.UidFetch(seqset, fields, messages)
+		done <- c.UIDFetch(seqset, fields, messages)
 	}()
 
 	tag, cmd := s.ScanCmd()
@@ -363,15 +363,15 @@ func TestClient_Fetch_Uid(t *testing.T) {
 	s.WriteString(tag + " OK UID FETCH completed\r\n")
 
 	if err := <-done; err != nil {
-		t.Fatalf("c.UidFetch() = %v", err)
+		t.Fatalf("c.UIDFetch() = %v", err)
 	}
 
 	msg := <-messages
 	if msg.SeqNum != 23 {
 		t.Errorf("First message has bad sequence number: %v", msg.SeqNum)
 	}
-	if msg.Uid != 42 {
-		t.Errorf("Message has bad UID: %v", msg.Uid)
+	if msg.UID != 42 {
+		t.Errorf("Message has bad UID: %v", msg.UID)
 	}
 	if len(msg.Flags) != 1 || msg.Flags[0] != "\\Seen" {
 		t.Errorf("Message has bad flags: %v", msg.Flags)
@@ -445,7 +445,7 @@ func TestClient_Store_Uid(t *testing.T) {
 
 	done := make(chan error, 1)
 	go func() {
-		done <- c.UidStore(seqset, imap.AddFlags, []interface{}{imap.DeletedFlag}, nil)
+		done <- c.UIDStore(seqset, imap.AddFlags, []interface{}{imap.DeletedFlag}, nil)
 	}()
 
 	tag, cmd := s.ScanCmd()
@@ -456,7 +456,7 @@ func TestClient_Store_Uid(t *testing.T) {
 	s.WriteString(tag + " OK STORE completed\r\n")
 
 	if err := <-done; err != nil {
-		t.Fatalf("c.UidStore() = %v", err)
+		t.Fatalf("c.UIDStore() = %v", err)
 	}
 }
 
@@ -495,7 +495,7 @@ func TestClient_Copy_Uid(t *testing.T) {
 
 	done := make(chan error, 1)
 	go func() {
-		done <- c.UidCopy(seqset, "Drafts")
+		done <- c.UIDCopy(seqset, "Drafts")
 	}()
 
 	tag, cmd := s.ScanCmd()
@@ -506,6 +506,6 @@ func TestClient_Copy_Uid(t *testing.T) {
 	s.WriteString(tag + " OK UID COPY completed\r\n")
 
 	if err := <-done; err != nil {
-		t.Fatalf("c.UidCopy() = %v", err)
+		t.Fatalf("c.UIDCopy() = %v", err)
 	}
 }
diff --git a/client/example_test.go b/client/example_test.go
index 8da6bda5..69d296f9 100644
--- a/client/example_test.go
+++ b/client/example_test.go
@@ -58,7 +58,7 @@ func ExampleClient() {
 	from := uint32(1)
 	to := mbox.Messages
 	if mbox.Messages > 3 {
-		// We're using unsigned integers here, only substract if the result is > 0
+		// We're using unsigned integers here, only subtract if the result is > 0
 		from = mbox.Messages - 3
 	}
 	seqset := new(imap.SeqSet)
diff --git a/commands/append.go b/commands/append.go
index d70b584e..b8f2cea0 100644
--- a/commands/append.go
+++ b/commands/append.go
@@ -44,7 +44,7 @@ func (cmd *Append) Command() *imap.Command {
 
 func (cmd *Append) Parse(fields []interface{}) (err error) {
 	if len(fields) < 2 {
-		return errors.New("No enough arguments")
+		return errors.New("no enough arguments")
 	}
 
 	// Parse mailbox name
@@ -60,7 +60,7 @@ func (cmd *Append) Parse(fields []interface{}) (err error) {
 	litIndex := len(fields) - 1
 	var ok bool
 	if cmd.Message, ok = fields[litIndex].(imap.Literal); !ok {
-		return errors.New("Message must be a literal")
+		return errors.New("message must be a literal")
 	}
 
 	// Remaining fields a optional
@@ -82,7 +82,7 @@ func (cmd *Append) Parse(fields []interface{}) (err error) {
 		// Parse date
 		if len(fields) > 0 {
 			if date, ok := fields[0].(string); !ok {
-				return errors.New("Date must be a string")
+				return errors.New("date must be a string")
 			} else if cmd.Date, err = time.Parse(imap.DateTimeLayout, date); err != nil {
 				return err
 			}
diff --git a/commands/authenticate.go b/commands/authenticate.go
index ec39a41b..64319b4e 100644
--- a/commands/authenticate.go
+++ b/commands/authenticate.go
@@ -48,12 +48,12 @@ func (cmd *Authenticate) Command() *imap.Command {
 
 func (cmd *Authenticate) Parse(fields []interface{}) error {
 	if len(fields) < 1 {
-		return errors.New("Not enough arguments")
+		return errors.New("not enough arguments")
 	}
 
 	var ok bool
 	if cmd.Mechanism, ok = fields[0].(string); !ok {
-		return errors.New("Mechanism must be a string")
+		return errors.New("mechanism must be a string")
 	}
 	cmd.Mechanism = strings.ToUpper(cmd.Mechanism)
 
@@ -63,7 +63,7 @@ func (cmd *Authenticate) Parse(fields []interface{}) error {
 
 	encodedResponse, ok := fields[1].(string)
 	if !ok {
-		return errors.New("Initial response must be a string")
+		return errors.New("initial response must be a string")
 	}
 	if encodedResponse == "=" {
 		cmd.InitialResponse = []byte{}
@@ -82,7 +82,7 @@ func (cmd *Authenticate) Parse(fields []interface{}) error {
 func (cmd *Authenticate) Handle(mechanisms map[string]sasl.Server, conn AuthenticateConn) error {
 	sasl, ok := mechanisms[cmd.Mechanism]
 	if !ok {
-		return errors.New("Unsupported mechanism")
+		return errors.New("unsupported mechanism")
 	}
 
 	scanner := bufio.NewScanner(conn)
diff --git a/commands/copy.go b/commands/copy.go
index 5258f35c..df89fc96 100644
--- a/commands/copy.go
+++ b/commands/copy.go
@@ -24,11 +24,11 @@ func (cmd *Copy) Command() *imap.Command {
 
 func (cmd *Copy) Parse(fields []interface{}) error {
 	if len(fields) < 2 {
-		return errors.New("No enough arguments")
+		return errors.New("not enough arguments")
 	}
 
 	if seqSet, ok := fields[0].(string); !ok {
-		return errors.New("Invalid sequence set")
+		return errors.New("invalid sequence set")
 	} else if seqSet, err := imap.ParseSeqSet(seqSet); err != nil {
 		return err
 	} else {
diff --git a/commands/create.go b/commands/create.go
index a1e6fe22..ac6e56a4 100644
--- a/commands/create.go
+++ b/commands/create.go
@@ -23,7 +23,7 @@ func (cmd *Create) Command() *imap.Command {
 
 func (cmd *Create) Parse(fields []interface{}) error {
 	if len(fields) < 1 {
-		return errors.New("No enough arguments")
+		return errors.New("not enough arguments")
 	}
 
 	if mailbox, err := imap.ParseString(fields[0]); err != nil {
diff --git a/commands/delete.go b/commands/delete.go
index 60f4da8a..5500b336 100644
--- a/commands/delete.go
+++ b/commands/delete.go
@@ -23,7 +23,7 @@ func (cmd *Delete) Command() *imap.Command {
 
 func (cmd *Delete) Parse(fields []interface{}) error {
 	if len(fields) < 1 {
-		return errors.New("No enough arguments")
+		return errors.New("not enough arguments")
 	}
 
 	if mailbox, err := imap.ParseString(fields[0]); err != nil {
diff --git a/commands/fetch.go b/commands/fetch.go
index cf45f755..5ca90697 100644
--- a/commands/fetch.go
+++ b/commands/fetch.go
@@ -27,12 +27,12 @@ func (cmd *Fetch) Command() *imap.Command {
 
 func (cmd *Fetch) Parse(fields []interface{}) error {
 	if len(fields) < 2 {
-		return errors.New("No enough arguments")
+		return errors.New("not enough arguments")
 	}
 
 	var err error
 	if seqset, ok := fields[0].(string); !ok {
-		return errors.New("Sequence set must be an atom")
+		return errors.New("sequence set must be an atom")
 	} else if cmd.SeqSet, err = imap.ParseSeqSet(seqset); err != nil {
 		return err
 	}
@@ -48,7 +48,7 @@ func (cmd *Fetch) Parse(fields []interface{}) error {
 			cmd.Items = append(cmd.Items, item.Expand()...)
 		}
 	default:
-		return errors.New("Items must be either a string or a list")
+		return errors.New("items must be either a string or a list")
 	}
 
 	return nil
diff --git a/commands/list.go b/commands/list.go
index 52686e9e..f2d71b20 100644
--- a/commands/list.go
+++ b/commands/list.go
@@ -34,7 +34,7 @@ func (cmd *List) Command() *imap.Command {
 
 func (cmd *List) Parse(fields []interface{}) error {
 	if len(fields) < 2 {
-		return errors.New("No enough arguments")
+		return errors.New("not enough arguments")
 	}
 
 	dec := utf7.Encoding.NewDecoder()
diff --git a/commands/login.go b/commands/login.go
index d0af0b50..8959b611 100644
--- a/commands/login.go
+++ b/commands/login.go
@@ -21,7 +21,7 @@ func (cmd *Login) Command() *imap.Command {
 
 func (cmd *Login) Parse(fields []interface{}) error {
 	if len(fields) < 2 {
-		return errors.New("Not enough arguments")
+		return errors.New("not enough arguments")
 	}
 
 	var err error
diff --git a/commands/rename.go b/commands/rename.go
index 37a5fa7f..9a7863c0 100644
--- a/commands/rename.go
+++ b/commands/rename.go
@@ -26,7 +26,7 @@ func (cmd *Rename) Command() *imap.Command {
 
 func (cmd *Rename) Parse(fields []interface{}) error {
 	if len(fields) < 2 {
-		return errors.New("No enough arguments")
+		return errors.New("not enough arguments")
 	}
 
 	dec := utf7.Encoding.NewDecoder()
diff --git a/commands/search.go b/commands/search.go
index 72f026c6..3807f680 100644
--- a/commands/search.go
+++ b/commands/search.go
@@ -29,16 +29,16 @@ func (cmd *Search) Command() *imap.Command {
 
 func (cmd *Search) Parse(fields []interface{}) error {
 	if len(fields) == 0 {
-		return errors.New("Missing search criteria")
+		return errors.New("missing search criteria")
 	}
 
 	// Parse charset
 	if f, ok := fields[0].(string); ok && strings.EqualFold(f, "CHARSET") {
 		if len(fields) < 2 {
-			return errors.New("Missing CHARSET value")
+			return errors.New("missing CHARSET value")
 		}
 		if cmd.Charset, ok = fields[1].(string); !ok {
-			return errors.New("Charset must be a string")
+			return errors.New("charset must be a string")
 		}
 		fields = fields[2:]
 	}
diff --git a/commands/select.go b/commands/select.go
index e881effe..41ebbefd 100644
--- a/commands/select.go
+++ b/commands/select.go
@@ -30,7 +30,7 @@ func (cmd *Select) Command() *imap.Command {
 
 func (cmd *Select) Parse(fields []interface{}) error {
 	if len(fields) < 1 {
-		return errors.New("No enough arguments")
+		return errors.New("not enough arguments")
 	}
 
 	if mailbox, err := imap.ParseString(fields[0]); err != nil {
diff --git a/commands/status.go b/commands/status.go
index 672dce5c..14c03c76 100644
--- a/commands/status.go
+++ b/commands/status.go
@@ -30,7 +30,7 @@ func (cmd *Status) Command() *imap.Command {
 
 func (cmd *Status) Parse(fields []interface{}) error {
 	if len(fields) < 2 {
-		return errors.New("No enough arguments")
+		return errors.New("not enough arguments")
 	}
 
 	if mailbox, err := imap.ParseString(fields[0]); err != nil {
@@ -48,7 +48,7 @@ func (cmd *Status) Parse(fields []interface{}) error {
 	cmd.Items = make([]imap.StatusItem, len(items))
 	for i, f := range items {
 		if s, ok := f.(string); !ok {
-			return errors.New("Got a non-string field in a STATUS command parameter")
+			return errors.New("got a non-string field in a STATUS command parameter")
 		} else {
 			cmd.Items[i] = imap.StatusItem(strings.ToUpper(s))
 		}
diff --git a/commands/store.go b/commands/store.go
index aeee3e62..4912e7e5 100644
--- a/commands/store.go
+++ b/commands/store.go
@@ -23,12 +23,12 @@ func (cmd *Store) Command() *imap.Command {
 
 func (cmd *Store) Parse(fields []interface{}) error {
 	if len(fields) < 3 {
-		return errors.New("No enough arguments")
+		return errors.New("not enough arguments")
 	}
 
 	seqset, ok := fields[0].(string)
 	if !ok {
-		return errors.New("Invalid sequence set")
+		return errors.New("invalid sequence set")
 	}
 	var err error
 	if cmd.SeqSet, err = imap.ParseSeqSet(seqset); err != nil {
@@ -36,7 +36,7 @@ func (cmd *Store) Parse(fields []interface{}) error {
 	}
 
 	if item, ok := fields[1].(string); !ok {
-		return errors.New("Item name must be a string")
+		return errors.New("item name must be a string")
 	} else {
 		cmd.Item = imap.StoreItem(strings.ToUpper(item))
 	}
diff --git a/commands/subscribe.go b/commands/subscribe.go
index 6540969c..53b9daef 100644
--- a/commands/subscribe.go
+++ b/commands/subscribe.go
@@ -23,7 +23,7 @@ func (cmd *Subscribe) Command() *imap.Command {
 
 func (cmd *Subscribe) Parse(fields []interface{}) error {
 	if len(fields) < 0 {
-		return errors.New("No enough arguments")
+		return errors.New("not enough arguments")
 	}
 
 	if mailbox, err := imap.ParseString(fields[0]); err != nil {
@@ -51,7 +51,7 @@ func (cmd *Unsubscribe) Command() *imap.Command {
 
 func (cmd *Unsubscribe) Parse(fields []interface{}) error {
 	if len(fields) < 0 {
-		return errors.New("No enogh arguments")
+		return errors.New("not enough arguments")
 	}
 
 	if mailbox, err := imap.ParseString(fields[0]); err != nil {
diff --git a/commands/uid.go b/commands/uid.go
index 979af144..8b60ae3f 100644
--- a/commands/uid.go
+++ b/commands/uid.go
@@ -7,13 +7,13 @@ import (
 	"github.com/emersion/go-imap"
 )
 
-// Uid is a UID command, as defined in RFC 3501 section 6.4.8. It wraps another
+// UID is a UID command, as defined in RFC 3501 section 6.4.8. It wraps another
 // command (e.g. wrapping a Fetch command will result in a UID FETCH).
-type Uid struct {
+type UID struct {
 	Cmd imap.Commander
 }
 
-func (cmd *Uid) Command() *imap.Command {
+func (cmd *UID) Command() *imap.Command {
 	inner := cmd.Cmd.Command()
 
 	args := []interface{}{imap.RawString(inner.Name)}
@@ -25,14 +25,14 @@ func (cmd *Uid) Command() *imap.Command {
 	}
 }
 
-func (cmd *Uid) Parse(fields []interface{}) error {
+func (cmd *UID) Parse(fields []interface{}) error {
 	if len(fields) < 0 {
-		return errors.New("No command name specified")
+		return errors.New("no command name specified")
 	}
 
 	name, ok := fields[0].(string)
 	if !ok {
-		return errors.New("Command name must be a string")
+		return errors.New("command name must be a string")
 	}
 
 	cmd.Cmd = &imap.Command{
diff --git a/go.mod b/go.mod
index 19859a28..662f702a 100644
--- a/go.mod
+++ b/go.mod
@@ -1,7 +1,10 @@
 module github.com/emersion/go-imap
 
 require (
+	github.com/alexkohler/prealloc v0.0.0-20181002111628-4fce4887dad9 // indirect
 	github.com/emersion/go-message v0.10.4-0.20190609165112-592ace5bc1ca
 	github.com/emersion/go-sasl v0.0.0-20190520160400-47d427600317
 	golang.org/x/text v0.3.2
 )
+
+go 1.13
diff --git a/go.sum b/go.sum
index c88e801e..494f4786 100644
--- a/go.sum
+++ b/go.sum
@@ -1,3 +1,5 @@
+github.com/alexkohler/prealloc v0.0.0-20181002111628-4fce4887dad9 h1:31kqHz4wQqRjuSSD66Nwb8QeNxA1Fr7PL7yGtCRoMhk=
+github.com/alexkohler/prealloc v0.0.0-20181002111628-4fce4887dad9/go.mod h1:CmbNRwpsIT6OOr1myakD2xc96sG7MWgs2VePr8EjW58=
 github.com/davecgh/go-spew v1.1.0 h1:ZDRjVQ15GmhC3fiQ8ni8+OwkZQO4DARzQgrnXU1Liz8=
 github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
 github.com/emersion/go-message v0.10.4-0.20190609165112-592ace5bc1ca h1:OYhqtJI4eOLvGtRIsUfP87VMJ1J/o6ks1tah9DlYkn4=
diff --git a/imap.go b/imap.go
index 37681f1d..4a24711a 100644
--- a/imap.go
+++ b/imap.go
@@ -14,8 +14,8 @@ type StatusItem string
 const (
 	StatusMessages    StatusItem = "MESSAGES"
 	StatusRecent      StatusItem = "RECENT"
-	StatusUidNext     StatusItem = "UIDNEXT"
-	StatusUidValidity StatusItem = "UIDVALIDITY"
+	StatusUIDNext     StatusItem = "UIDNEXT"
+	StatusUIDValidity StatusItem = "UIDVALIDITY"
 	StatusUnseen      StatusItem = "UNSEEN"
 )
 
@@ -39,7 +39,7 @@ const (
 	FetchRFC822Header  FetchItem = "RFC822.HEADER"
 	FetchRFC822Size    FetchItem = "RFC822.SIZE"
 	FetchRFC822Text    FetchItem = "RFC822.TEXT"
-	FetchUid           FetchItem = "UID"
+	FetchUID           FetchItem = "UID"
 )
 
 // Expand expands the item if it's a macro.
@@ -94,7 +94,7 @@ func ParseFlagsOp(item StoreItem) (op FlagsOp, silent bool, err error) {
 	op = FlagsOp(itemStr)
 
 	if op != SetFlags && op != AddFlags && op != RemoveFlags {
-		err = errors.New("Unsupported STORE operation")
+		err = errors.New("unsupported STORE operation")
 	}
 	return
 }
diff --git a/mailbox.go b/mailbox.go
index 2371bdcf..315086c4 100644
--- a/mailbox.go
+++ b/mailbox.go
@@ -51,7 +51,7 @@ type MailboxInfo struct {
 // Parse mailbox info from fields.
 func (info *MailboxInfo) Parse(fields []interface{}) error {
 	if len(fields) < 3 {
-		return errors.New("Mailbox info needs at least 3 fields")
+		return errors.New("mailbox info needs at least 3 fields")
 	}
 
 	var err error
@@ -61,7 +61,7 @@ func (info *MailboxInfo) Parse(fields []interface{}) error {
 
 	var ok bool
 	if info.Delimiter, ok = fields[1].(string); !ok {
-		return errors.New("Mailbox delimiter must be a string")
+		return errors.New("mailbox delimiter must be a string")
 	}
 
 	if name, err := ParseString(fields[2]); err != nil {
@@ -169,10 +169,10 @@ type MailboxStatus struct {
 	// The number of unread messages.
 	Unseen uint32
 	// The next UID.
-	UidNext uint32
+	UIDNext uint32
 	// Together with a UID, it is a unique identifier for a message.
 	// Must be greater than or equal to 1.
-	UidValidity uint32
+	UIDValidity uint32
 }
 
 // Create a new mailbox status that will contain the specified items.
@@ -211,10 +211,10 @@ func (status *MailboxStatus) Parse(fields []interface{}) error {
 				status.Recent, err = ParseNumber(f)
 			case StatusUnseen:
 				status.Unseen, err = ParseNumber(f)
-			case StatusUidNext:
-				status.UidNext, err = ParseNumber(f)
-			case StatusUidValidity:
-				status.UidValidity, err = ParseNumber(f)
+			case StatusUIDNext:
+				status.UIDNext, err = ParseNumber(f)
+			case StatusUIDValidity:
+				status.UIDValidity, err = ParseNumber(f)
 			default:
 				status.Items[k] = f
 			}
@@ -238,10 +238,10 @@ func (status *MailboxStatus) Format() []interface{} {
 			v = status.Recent
 		case StatusUnseen:
 			v = status.Unseen
-		case StatusUidNext:
-			v = status.UidNext
-		case StatusUidValidity:
-			v = status.UidValidity
+		case StatusUIDNext:
+			v = status.UIDNext
+		case StatusUIDValidity:
+			v = status.UIDValidity
 		}
 
 		fields = append(fields, RawString(k), v)
diff --git a/mailbox_test.go b/mailbox_test.go
index 5d5eb70d..19e67673 100644
--- a/mailbox_test.go
+++ b/mailbox_test.go
@@ -140,14 +140,14 @@ var mailboxStatusTests = [...]struct {
 				imap.StatusMessages:    nil,
 				imap.StatusRecent:      nil,
 				imap.StatusUnseen:      nil,
-				imap.StatusUidNext:     nil,
-				imap.StatusUidValidity: nil,
+				imap.StatusUIDNext:     nil,
+				imap.StatusUIDValidity: nil,
 			},
 			Messages:    42,
 			Recent:      1,
 			Unseen:      6,
-			UidNext:     65536,
-			UidValidity: 4242,
+			UIDNext:     65536,
+			UIDValidity: 4242,
 		},
 	},
 }
diff --git a/message.go b/message.go
index 7a001415..1b6b8bc3 100644
--- a/message.go
+++ b/message.go
@@ -68,7 +68,7 @@ func ParseParamList(fields []interface{}) (map[string]string, error) {
 	for i, f := range fields {
 		p, err := ParseString(f)
 		if err != nil {
-			return nil, errors.New("Parameter list contains a non-string: " + err.Error())
+			return nil, errors.New("parameter list contains a non-string: " + err.Error())
 		}
 
 		if i%2 == 0 {
@@ -80,7 +80,7 @@ func ParseParamList(fields []interface{}) (map[string]string, error) {
 	}
 
 	if k != "" {
-		return nil, errors.New("Parameter list contains a key without a value")
+		return nil, errors.New("parameter list contains a key without a value")
 	}
 	return params, nil
 }
@@ -154,7 +154,7 @@ type Message struct {
 	// The message size.
 	Size uint32
 	// The message unique identifier. It must be greater than or equal to 1.
-	Uid uint32
+	UID uint32
 	// The message body sections.
 	Body map[*BodySectionName]Literal
 
@@ -238,8 +238,8 @@ func (m *Message) Parse(fields []interface{}) error {
 				m.InternalDate, _ = time.Parse(DateTimeLayout, date)
 			case FetchRFC822Size:
 				m.Size, _ = ParseNumber(f)
-			case FetchUid:
-				m.Uid, _ = ParseNumber(f)
+			case FetchUID:
+				m.UID, _ = ParseNumber(f)
 			default:
 				// Likely to be a section of the body
 				// First check that the section name is correct
@@ -277,8 +277,8 @@ func (m *Message) formatItem(k FetchItem) []interface{} {
 		v = m.InternalDate
 	case FetchRFC822Size:
 		v = m.Size
-	case FetchUid:
-		v = m.Uid
+	case FetchUID:
+		v = m.UID
 	default:
 		for section, literal := range m.Body {
 			if section.value == k {
@@ -357,12 +357,12 @@ func (section *BodySectionName) parse(s string) error {
 
 	partStart := strings.Index(s, "[")
 	if partStart == -1 {
-		return errors.New("Invalid body section name: must contain an open bracket")
+		return errors.New("invalid body section name: must contain an open bracket")
 	}
 
 	partEnd := strings.LastIndex(s, "]")
 	if partEnd == -1 {
-		return errors.New("Invalid body section name: must contain a close bracket")
+		return errors.New("invalid body section name: must contain a close bracket")
 	}
 
 	name := s[:partStart]
@@ -372,7 +372,7 @@ func (section *BodySectionName) parse(s string) error {
 	if name == "BODY.PEEK" {
 		section.Peek = true
 	} else if name != "BODY" {
-		return errors.New("Invalid body section name")
+		return errors.New("invalid body section name")
 	}
 
 	b := bytes.NewBufferString(part + string(cr) + string(lf))
@@ -388,7 +388,7 @@ func (section *BodySectionName) parse(s string) error {
 
 	if len(partial) > 0 {
 		if !strings.HasPrefix(partial, "<") || !strings.HasSuffix(partial, ">") {
-			return errors.New("Invalid body section name: invalid partial")
+			return errors.New("invalid body section name: invalid partial")
 		}
 		partial = partial[1 : len(partial)-1]
 
@@ -396,13 +396,13 @@ func (section *BodySectionName) parse(s string) error {
 
 		var from, length int
 		if from, err = strconv.Atoi(partialParts[0]); err != nil {
-			return errors.New("Invalid body section name: invalid partial: invalid from: " + err.Error())
+			return errors.New("invalid body section name: invalid partial: invalid from: " + err.Error())
 		}
 		section.Partial = []int{from}
 
 		if len(partialParts) == 2 {
 			if length, err = strconv.Atoi(partialParts[1]); err != nil {
-				return errors.New("Invalid body section name: invalid partial: invalid length: " + err.Error())
+				return errors.New("invalid body section name: invalid partial: invalid length: " + err.Error())
 			}
 			section.Partial = append(section.Partial, length)
 		}
@@ -513,7 +513,7 @@ func (part *BodyPartName) parse(fields []interface{}) error {
 
 	name, ok := fields[0].(string)
 	if !ok {
-		return errors.New("Invalid body section name: part name must be a string")
+		return errors.New("invalid body section name: part name must be a string")
 	}
 
 	args := fields[1:]
@@ -535,7 +535,7 @@ loop:
 			return errors.New("Invalid body part name: " + err.Error())
 		}
 		if index <= 0 {
-			return errors.New("Invalid body part name: index <= 0")
+			return errors.New("invalid body part name: index <= 0")
 		}
 
 		part.Path = append(part.Path, index)
@@ -549,7 +549,7 @@ loop:
 
 		names, ok := args[0].([]interface{})
 		if !ok {
-			return errors.New("Invalid body part name: HEADER.FIELDS must have a list argument")
+			return errors.New("invalid body part name: HEADER.FIELDS must have a list argument")
 		}
 
 		for _, namei := range names {
@@ -723,10 +723,10 @@ type Envelope struct {
 	Cc []*Address
 	// The Bcc header addresses.
 	Bcc []*Address
-	// The In-Reply-To header. Contains the parent Message-Id.
+	// The In-Reply-To header. Contains the parent Message-ID.
 	InReplyTo string
-	// The Message-Id header.
-	MessageId string
+	// The Message-ID header.
+	MessageID string
 }
 
 // Parse an envelope from fields.
@@ -762,8 +762,8 @@ func (e *Envelope) Parse(fields []interface{}) error {
 	if inReplyTo, ok := fields[8].(string); ok {
 		e.InReplyTo = inReplyTo
 	}
-	if msgId, ok := fields[9].(string); ok {
-		e.MessageId = msgId
+	if msgID, ok := fields[9].(string); ok {
+		e.MessageID = msgID
 	}
 
 	return nil
@@ -781,7 +781,7 @@ func (e *Envelope) Format() (fields []interface{}) {
 		FormatAddressList(e.Cc),
 		FormatAddressList(e.Bcc),
 		e.InReplyTo,
-		e.MessageId,
+		e.MessageID,
 	}
 }
 
@@ -797,8 +797,8 @@ type BodyStructure struct {
 	// The MIME parameters.
 	Params map[string]string
 
-	// The Content-Id header.
-	Id string
+	// The Content-ID header.
+	ID string
 	// The Content-Description header.
 	Description string
 	// The Content-Encoding header.
@@ -906,7 +906,7 @@ func (bs *BodyStructure) Parse(fields []interface{}) error {
 		}
 	case string: // A non-multipart body part
 		if len(fields) < 7 {
-			return errors.New("Non-multipart body part doesn't have 7 fields")
+			return errors.New("non-multipart body part doesn't have 7 fields")
 		}
 
 		bs.MIMEType, _ = fields[0].(string)
@@ -915,7 +915,7 @@ func (bs *BodyStructure) Parse(fields []interface{}) error {
 		params, _ := fields[2].([]interface{})
 		bs.Params, _ = parseHeaderParamList(params)
 
-		bs.Id, _ = fields[3].(string)
+		bs.ID, _ = fields[3].(string)
 		if desc, err := ParseString(fields[4]); err == nil {
 			bs.Description, _ = decodeHeader(desc)
 		}
@@ -927,7 +927,7 @@ func (bs *BodyStructure) Parse(fields []interface{}) error {
 		// Type-specific fields
 		if strings.EqualFold(bs.MIMEType, "message") && strings.EqualFold(bs.MIMESubType, "rfc822") {
 			if len(fields)-end < 3 {
-				return errors.New("Missing type-specific fields for message/rfc822")
+				return errors.New("missing type-specific fields for message/rfc822")
 			}
 
 			envelope, _ := fields[end].([]interface{})
@@ -944,7 +944,7 @@ func (bs *BodyStructure) Parse(fields []interface{}) error {
 		}
 		if strings.EqualFold(bs.MIMEType, "text") {
 			if len(fields)-end < 1 {
-				return errors.New("Missing type-specific fields for text/*")
+				return errors.New("missing type-specific fields for text/*")
 			}
 
 			bs.Lines, _ = ParseNumber(fields[end])
@@ -1026,8 +1026,8 @@ func (bs *BodyStructure) Format() (fields []interface{}) {
 		fields[1] = bs.MIMESubType
 		fields[2] = formatHeaderParamList(bs.Params)
 
-		if bs.Id != "" {
-			fields[3] = bs.Id
+		if bs.ID != "" {
+			fields[3] = bs.ID
 		}
 		if bs.Description != "" {
 			fields[4] = encodeHeader(bs.Description)
diff --git a/message_test.go b/message_test.go
index 71646e40..5e0d2f9d 100644
--- a/message_test.go
+++ b/message_test.go
@@ -55,15 +55,15 @@ var messageTests = []struct {
 				FetchBody:       nil,
 				FetchFlags:      nil,
 				FetchRFC822Size: nil,
-				FetchUid:        nil,
+				FetchUID:        nil,
 			},
 			Body:          map[*BodySectionName]Literal{},
 			Envelope:      envelopeTests[0].envelope,
 			BodyStructure: bodyStructureTests[0].bodyStructure,
 			Flags:         []string{SeenFlag, AnsweredFlag},
 			Size:          4242,
-			Uid:           2424,
-			itemsOrder:    []FetchItem{FetchEnvelope, FetchBody, FetchFlags, FetchRFC822Size, FetchUid},
+			UID:           2424,
+			itemsOrder:    []FetchItem{FetchEnvelope, FetchBody, FetchFlags, FetchRFC822Size, FetchUID},
 		},
 		fields: []interface{}{
 			RawString("ENVELOPE"), envelopeTests[0].fields,
@@ -165,8 +165,8 @@ var bodySectionNameTests = []struct {
 		parsed: &BodySectionName{BodyPartName: BodyPartName{Specifier: HeaderSpecifier, Fields: []string{"From", "To"}}},
 	},
 	{
-		raw:    "BODY[HEADER.FIELDS.NOT (Content-Id)]",
-		parsed: &BodySectionName{BodyPartName: BodyPartName{Specifier: HeaderSpecifier, Fields: []string{"Content-Id"}, NotFields: true}},
+		raw:    "BODY[HEADER.FIELDS.NOT (Content-ID)]",
+		parsed: &BodySectionName{BodyPartName: BodyPartName{Specifier: HeaderSpecifier, Fields: []string{"Content-ID"}, NotFields: true}},
 	},
 }
 
@@ -267,7 +267,7 @@ var envelopeTests = []struct {
 			Cc:        []*Address{},
 			Bcc:       []*Address{},
 			InReplyTo: "42@example.org",
-			MessageId: "43@example.org",
+			MessageID: "43@example.org",
 		},
 		fields: []interface{}{
 			"Tue, 10 Nov 2009 23:00:00 -0600",
@@ -447,7 +447,7 @@ var bodyStructureTests = []struct {
 			MIMEType:    "image",
 			MIMESubType: "jpeg",
 			Params:      map[string]string{},
-			Id:          "<foo4%25foo1@bar.net>",
+			ID:          "<foo4%25foo1@bar.net>",
 			Description: "A picture of cat",
 			Encoding:    "base64",
 			Size:        4242,
diff --git a/read.go b/read.go
index 135b5aaf..70d35e61 100644
--- a/read.go
+++ b/read.go
@@ -79,7 +79,7 @@ func ParseNumber(f interface{}) (uint32, error) {
 		return 0, newParseError("expected a number, got a non-atom")
 	}
 
-	nbr, err := strconv.ParseUint(string(s), 10, 32)
+	nbr, err := strconv.ParseUint(s, 10, 32)
 	if err != nil {
 		return 0, &parseError{err}
 	}
diff --git a/response.go b/response.go
index 611d03e6..bd37bcc8 100644
--- a/response.go
+++ b/response.go
@@ -122,7 +122,7 @@ func (r *DataResp) WriteTo(w *Writer) error {
 		tag = RawString("*")
 	}
 
-	fields := []interface{}{RawString(tag)}
+	fields := []interface{}{tag}
 	fields = append(fields, r.Fields...)
 	return w.writeLine(fields...)
 }
diff --git a/responses/list.go b/responses/list.go
index e080fc16..f6d09855 100644
--- a/responses/list.go
+++ b/responses/list.go
@@ -20,9 +20,8 @@ type List struct {
 func (r *List) Name() string {
 	if r.Subscribed {
 		return lsubName
-	} else {
-		return listName
 	}
+	return listName
 }
 
 func (r *List) Handle(resp imap.Resp) error {
diff --git a/responses/select.go b/responses/select.go
index e450963b..3bdf5d96 100644
--- a/responses/select.go
+++ b/responses/select.go
@@ -41,11 +41,11 @@ func (r *Select) Handle(resp imap.Resp) error {
 			flags, _ := resp.Arguments[0].([]interface{})
 			mbox.PermanentFlags, _ = imap.ParseStringList(flags)
 		case "UIDNEXT":
-			mbox.UidNext, _ = imap.ParseNumber(resp.Arguments[0])
-			item = imap.StatusUidNext
+			mbox.UIDNext, _ = imap.ParseNumber(resp.Arguments[0])
+			item = imap.StatusUIDNext
 		case "UIDVALIDITY":
-			mbox.UidValidity, _ = imap.ParseNumber(resp.Arguments[0])
-			item = imap.StatusUidValidity
+			mbox.UIDValidity, _ = imap.ParseNumber(resp.Arguments[0])
+			item = imap.StatusUIDValidity
 		default:
 			return ErrUnhandled
 		}
@@ -115,21 +115,21 @@ func (r *Select) WriteTo(w *imap.Writer) error {
 			if err := res.WriteTo(w); err != nil {
 				return err
 			}
-		case imap.StatusUidNext:
+		case imap.StatusUIDNext:
 			statusRes := &imap.StatusResp{
 				Type:      imap.StatusRespOk,
-				Code:      imap.CodeUidNext,
-				Arguments: []interface{}{mbox.UidNext},
+				Code:      imap.CodeUIDNext,
+				Arguments: []interface{}{mbox.UIDNext},
 				Info:      "Predicted next UID",
 			}
 			if err := statusRes.WriteTo(w); err != nil {
 				return err
 			}
-		case imap.StatusUidValidity:
+		case imap.StatusUIDValidity:
 			statusRes := &imap.StatusResp{
 				Type:      imap.StatusRespOk,
-				Code:      imap.CodeUidValidity,
-				Arguments: []interface{}{mbox.UidValidity},
+				Code:      imap.CodeUIDValidity,
+				Arguments: []interface{}{mbox.UIDValidity},
 				Info:      "UIDs valid",
 			}
 			if err := statusRes.WriteTo(w); err != nil {
diff --git a/search.go b/search.go
index 14d3f65b..9851f372 100644
--- a/search.go
+++ b/search.go
@@ -60,7 +60,7 @@ func popSearchField(fields []interface{}) (interface{}, []interface{}, error) {
 // only if it matches each one of its fields.
 type SearchCriteria struct {
 	SeqNum *SeqSet // Sequence number is in sequence set
-	Uid    *SeqSet // UID is in sequence set
+	UID    *SeqSet // UID is in sequence set
 
 	// Time and timezone are ignored
 	Since      time.Time // Internal date is since this date
@@ -237,7 +237,7 @@ func (c *SearchCriteria) parseField(fields []interface{}, charsetReader func(io.
 	case "UID":
 		if f, fields, err = popSearchField(fields); err != nil {
 			return nil, err
-		} else if c.Uid, err = ParseSeqSet(maybeString(f)); err != nil {
+		} else if c.UID, err = ParseSeqSet(maybeString(f)); err != nil {
 			return nil, err
 		}
 	case "UNANSWERED", "UNDELETED", "UNDRAFT", "UNFLAGGED", "UNSEEN":
@@ -278,8 +278,8 @@ func (c *SearchCriteria) Format() []interface{} {
 	if c.SeqNum != nil {
 		fields = append(fields, c.SeqNum)
 	}
-	if c.Uid != nil {
-		fields = append(fields, RawString("UID"), c.Uid)
+	if c.UID != nil {
+		fields = append(fields, RawString("UID"), c.UID)
 	}
 
 	if !c.Since.IsZero() && !c.Before.IsZero() && c.Before.Sub(c.Since) == 24*time.Hour {
diff --git a/search_test.go b/search_test.go
index 6d1af813..bd381fcb 100644
--- a/search_test.go
+++ b/search_test.go
@@ -31,7 +31,7 @@ var searchCriteriaTests = []struct {
 			`OR (ON "5-Nov-1984" DRAFT FLAGGED UNANSWERED UNDELETED OLD) (UNDRAFT UNFLAGGED UNSEEN))`,
 		criteria: &SearchCriteria{
 			SeqNum:     searchSeqSet1,
-			Uid:        searchSeqSet2,
+			UID:        searchSeqSet2,
 			Since:      searchDate2,
 			Before:     searchDate1,
 			SentSince:  searchDate2,
diff --git a/seqset.go b/seqset.go
index abe6afc1..f6451694 100644
--- a/seqset.go
+++ b/seqset.go
@@ -150,11 +150,11 @@ func (s *SeqSet) AddNum(q ...uint32) {
 }
 
 // AddRange inserts a new sequence range into the set.
-func (s *SeqSet) AddRange(Start, Stop uint32) {
-	if (Stop < Start && Stop != 0) || Start == 0 {
-		s.insert(Seq{Stop, Start})
+func (s *SeqSet) AddRange(start, stop uint32) {
+	if (stop < start && stop != 0) || start == 0 {
+		s.insert(Seq{stop, start})
 	} else {
-		s.insert(Seq{Start, Stop})
+		s.insert(Seq{start, stop})
 	}
 }
 
@@ -252,15 +252,15 @@ func (s *SeqSet) insert(v Seq) {
 
 // insertAt inserts a new sequence value v at index i, resizing s.Set as needed.
 func (s *SeqSet) insertAt(i int, v Seq) {
-	if n := len(s.Set); i == n {
+	n := len(s.Set)
+	switch {
+	case i == n:
 		// insert at the end
 		s.Set = append(s.Set, v)
-		return
-	} else if n < cap(s.Set) {
-		// enough space, shift everything at and after i to the right
+	case n < cap(s.Set):
 		s.Set = s.Set[:n+1]
 		copy(s.Set[i+1:], s.Set[i:])
-	} else {
+	default:
 		// allocate new slice and copy everything, n is at least 1
 		set := make([]Seq, n+1, n*2)
 		copy(set, s.Set[:i])
diff --git a/seqset_test.go b/seqset_test.go
index 4762bb34..807e974e 100644
--- a/seqset_test.go
+++ b/seqset_test.go
@@ -350,13 +350,13 @@ func TestSeqMerge(T *testing.T) {
 			T.Errorf("parseSeq(%q) unexpected error; %v", test.t, err)
 			continue
 		}
-		test_ok := test.out != ""
+		testOK := test.out != ""
 		for i := 0; i < 2; i++ {
-			if !test_ok {
+			if !testOK {
 				test.out = test.s
 			}
 			out, ok := s.Merge(t)
-			if out.String() != test.out || ok != test_ok {
+			if out.String() != test.out || ok != testOK {
 				T.Errorf("%q.Merge(%q) expected %q; got %q", test.s, test.t, test.out, out)
 			}
 			// Swap s & t, result should be identical
@@ -539,13 +539,13 @@ func TestSeqSetInfo(t *testing.T) {
 		if str := s.String(); str != test.s {
 			t.Errorf("%q.String() expected %q; got %q", test.s, test.s, str)
 		}
-		test_empty := len(test.s) == 0
-		if s.Empty() != test_empty {
-			t.Errorf("%q.Empty() expected %v", test.s, test_empty)
+		testEmpty := len(test.s) == 0
+		if s.Empty() != testEmpty {
+			t.Errorf("%q.Empty() expected %v", test.s, testEmpty)
 		}
-		test_dynamic := !test_empty && test.s[len(test.s)-1] == '*'
-		if s.Dynamic() != test_dynamic {
-			t.Errorf("%q.Dynamic() expected %v", test.s, test_dynamic)
+		testDynamic := !testEmpty && test.s[len(test.s)-1] == '*'
+		if s.Dynamic() != testDynamic {
+			t.Errorf("%q.Dynamic() expected %v", test.s, testDynamic)
 		}
 	}
 }
diff --git a/server/cmd_auth.go b/server/cmd_auth.go
index ce25f7f7..d702b741 100644
--- a/server/cmd_auth.go
+++ b/server/cmd_auth.go
@@ -11,7 +11,7 @@ import (
 
 // imap errors in Authenticated state.
 var (
-	ErrNotAuthenticated = errors.New("Not authenticated")
+	ErrNotAuthenticated = errors.New("not authenticated")
 )
 
 type Select struct {
@@ -31,7 +31,7 @@ func (cmd *Select) Handle(conn Conn) error {
 
 	items := []imap.StatusItem{
 		imap.StatusMessages, imap.StatusRecent, imap.StatusUnseen,
-		imap.StatusUidNext, imap.StatusUidValidity,
+		imap.StatusUIDNext, imap.StatusUIDValidity,
 	}
 
 	status, err := mbox.Status(items)
diff --git a/server/cmd_noauth.go b/server/cmd_noauth.go
index ac221cc7..44c63f02 100644
--- a/server/cmd_noauth.go
+++ b/server/cmd_noauth.go
@@ -12,8 +12,8 @@ import (
 
 // IMAP errors in Not Authenticated state.
 var (
-	ErrAlreadyAuthenticated = errors.New("Already authenticated")
-	ErrAuthDisabled         = errors.New("Authentication disabled")
+	ErrAlreadyAuthenticated = errors.New("already authenticated")
+	ErrAuthDisabled         = errors.New("authentication disabled")
 )
 
 type StartTLS struct {
diff --git a/server/cmd_selected.go b/server/cmd_selected.go
index f57623bd..0af3f3d5 100644
--- a/server/cmd_selected.go
+++ b/server/cmd_selected.go
@@ -10,16 +10,16 @@ import (
 
 // imap errors in Selected state.
 var (
-	ErrNoMailboxSelected = errors.New("No mailbox selected")
-	ErrMailboxReadOnly   = errors.New("Mailbox opened in read-only mode")
+	ErrNoMailboxSelected = errors.New("no mailbox selected")
+	ErrMailboxReadOnly   = errors.New("mailbox opened in read-only mode")
 )
 
 // A command handler that supports UIDs.
-type UidHandler interface {
+type UIDHandler interface {
 	Handler
 
 	// Handle this command using UIDs for a given connection.
-	UidHandle(conn Conn) error
+	UIDhandle(conn Conn) error
 }
 
 type Check struct {
@@ -138,7 +138,7 @@ func (cmd *Search) Handle(conn Conn) error {
 	return cmd.handle(false, conn)
 }
 
-func (cmd *Search) UidHandle(conn Conn) error {
+func (cmd *Search) UIDhandle(conn Conn) error {
 	return cmd.handle(true, conn)
 }
 
@@ -172,16 +172,16 @@ func (cmd *Fetch) Handle(conn Conn) error {
 	return cmd.handle(false, conn)
 }
 
-func (cmd *Fetch) UidHandle(conn Conn) error {
+func (cmd *Fetch) UIDhandle(conn Conn) error {
 	// Append UID to the list of requested items if it isn't already present
-	hasUid := false
+	hasUID := false
 	for _, item := range cmd.Items {
 		if item == "UID" {
-			hasUid = true
+			hasUID = true
 			break
 		}
 	}
-	if !hasUid {
+	if !hasUID {
 		cmd.Items = append(cmd.Items, "UID")
 	}
 
@@ -209,7 +209,7 @@ func (cmd *Store) handle(uid bool, conn Conn) error {
 
 	flagsList, ok := cmd.Value.([]interface{})
 	if !ok {
-		return errors.New("Flags must be a list")
+		return errors.New("flags must be a list")
 	}
 	flags, err := imap.ParseStringList(flagsList)
 	if err != nil {
@@ -251,7 +251,7 @@ func (cmd *Store) Handle(conn Conn) error {
 	return cmd.handle(false, conn)
 }
 
-func (cmd *Store) UidHandle(conn Conn) error {
+func (cmd *Store) UIDhandle(conn Conn) error {
 	return cmd.handle(true, conn)
 }
 
@@ -272,27 +272,27 @@ func (cmd *Copy) Handle(conn Conn) error {
 	return cmd.handle(false, conn)
 }
 
-func (cmd *Copy) UidHandle(conn Conn) error {
+func (cmd *Copy) UIDhandle(conn Conn) error {
 	return cmd.handle(true, conn)
 }
 
-type Uid struct {
-	commands.Uid
+type UID struct {
+	commands.UID
 }
 
-func (cmd *Uid) Handle(conn Conn) error {
+func (cmd *UID) Handle(conn Conn) error {
 	inner := cmd.Cmd.Command()
 	hdlr, err := conn.commandHandler(inner)
 	if err != nil {
 		return err
 	}
 
-	uidHdlr, ok := hdlr.(UidHandler)
+	uidHdlr, ok := hdlr.(UIDHandler)
 	if !ok {
-		return errors.New("Command unsupported with UID")
+		return errors.New("command unsupported with UID")
 	}
 
-	if err := uidHdlr.UidHandle(conn); err != nil {
+	if err := uidHdlr.UIDhandle(conn); err != nil {
 		return err
 	}
 
diff --git a/server/conn.go b/server/conn.go
index 7cad37b5..4456bef5 100644
--- a/server/conn.go
+++ b/server/conn.go
@@ -337,7 +337,6 @@ func (c *conn) serve(conn Conn) (err error) {
 		}
 
 		if res != nil {
-
 			if err := c.WriteResp(res); err != nil {
 				c.s.ErrorLog.Println("cannot write response:", err)
 				continue
@@ -361,7 +360,7 @@ func (c *conn) WaitReady() {
 func (c *conn) commandHandler(cmd *imap.Command) (hdlr Handler, err error) {
 	newHandler := c.s.Command(cmd.Name)
 	if newHandler == nil {
-		err = errors.New("Unknown command")
+		err = errors.New("unknown command")
 		return
 	}
 
diff --git a/server/server.go b/server/server.go
index 25621de0..521aea20 100644
--- a/server/server.go
+++ b/server/server.go
@@ -136,7 +136,7 @@ func New(bkd backend.Backend) *Server {
 		sasl.Plain: func(conn Conn) sasl.Server {
 			return sasl.NewPlainServer(func(identity, username, password string) error {
 				if identity != "" && identity != username {
-					return errors.New("Identities not supported")
+					return errors.New("identities not supported")
 				}
 
 				user, err := bkd.Login(conn.Info(), username, password)
@@ -188,7 +188,7 @@ func New(bkd backend.Backend) *Server {
 		"FETCH":   func() Handler { return &Fetch{} },
 		"STORE":   func() Handler { return &Store{} },
 		"COPY":    func() Handler { return &Copy{} },
-		"UID":     func() Handler { return &Uid{} },
+		"UID":     func() Handler { return &UID{} },
 	}
 
 	return s
@@ -207,7 +207,7 @@ func (s *Server) Serve(l net.Listener) error {
 		delete(s.listeners, l)
 	}()
 
-	updater, ok := s.Backend.(backend.BackendUpdater)
+	updater, ok := s.Backend.(backend.Updater)
 	if ok {
 		s.Updates = updater.Updates()
 		go s.listenUpdates()
diff --git a/status.go b/status.go
index 86a95b78..12fe76b3 100644
--- a/status.go
+++ b/status.go
@@ -51,8 +51,8 @@ const (
 	CodeReadOnly       StatusRespCode = "READ-ONLY"
 	CodeReadWrite      StatusRespCode = "READ-WRITE"
 	CodeTryCreate      StatusRespCode = "TRYCREATE"
-	CodeUidNext        StatusRespCode = "UIDNEXT"
-	CodeUidValidity    StatusRespCode = "UIDVALIDITY"
+	CodeUIDNext        StatusRespCode = "UIDNEXT"
+	CodeUIDValidity    StatusRespCode = "UIDVALIDITY"
 	CodeUnseen         StatusRespCode = "UNSEEN"
 )
 
@@ -94,7 +94,7 @@ func (r *StatusResp) WriteTo(w *Writer) error {
 		tag = "*"
 	}
 
-	if err := w.writeFields([]interface{}{RawString(tag), RawString(r.Type)}); err != nil {
+	if err := w.writeFields([]interface{}{tag, RawString(r.Type)}); err != nil {
 		return err
 	}
 
diff --git a/utf7/decoder.go b/utf7/decoder.go
index 1c5f1c4f..617825ff 100644
--- a/utf7/decoder.go
+++ b/utf7/decoder.go
@@ -109,15 +109,17 @@ func decode(b64 []byte) []byte {
 	// (if padding is required), UTF-16-BE bytes, and decoded UTF-8 bytes.
 	// Since a 2-byte UTF-16 sequence may expand into a 3-byte UTF-8 sequence,
 	// double the space allocation for UTF-8.
-	if n := len(b64); b64[n-1] == '=' {
+	n1 := len(b64)
+	switch {
+	case b64[n1-1] == '=':
 		return nil
-	} else if n&3 == 0 {
-		b = make([]byte, b64Enc.DecodedLen(n)*3)
-	} else {
-		n += 4 - n&3
-		b = make([]byte, n+b64Enc.DecodedLen(n)*3)
-		copy(b[copy(b, b64):n], []byte("=="))
-		b64, b = b[:n], b[n:]
+	case n1&3 == 0:
+		b = make([]byte, b64Enc.DecodedLen(n1)*3)
+	default:
+		n1 += 4 - n1&3
+		b = make([]byte, n1+b64Enc.DecodedLen(n1)*3)
+		copy(b[copy(b, b64):n1], []byte("=="))
+		b64, b = b[:n1], b[n1:]
 	}
 
 	// Decode Base64 into the first 1/3rd of b
diff --git a/write.go b/write.go
index aa17deb9..e9394620 100644
--- a/write.go
+++ b/write.go
@@ -36,7 +36,7 @@ func FormatStringList(list []string) (fields []interface{}) {
 }
 
 // Check if a string is 8-bit clean.
-func isAscii(s string) bool {
+func isASCII(s string) bool {
 	for _, c := range s {
 		if c > unicode.MaxASCII || unicode.IsControl(c) {
 			return false
@@ -77,7 +77,7 @@ func (w *Writer) writeQuoted(s string) error {
 }
 
 func (w *Writer) writeQuotedOrLiteral(s string) error {
-	if !isAscii(s) {
+	if !isASCII(s) {
 		// IMAP doesn't allow 8-bit data outside literals
 		return w.writeLiteral(bytes.NewBufferString(s))
 	}