Hi!

I've noticed that if Message-ID (or any other header using msg-id) has more than one "@" character than parsing via parseMsgID() from header.go fails with:

missing '>' in msg-id

as it expects to consume() special chars in the fallowing order: < , @ , >

i.e.

Message-ID: <113c01d86b4a$53bb4230$fa9e45a$@appmanager@yahoo.com>

I'm not sure if using two or more "@" characters in msg-id is correct but I've already seen a few of this headers in the wild.