Jon at WizardIsHungry 
is an unhappy Mail user.
He has three accounts, a Gmail account and two IMAP ones, but the mailboxes won’t behave the way he wants them to (as you can see on the right).
It’s a mess. One IMAP account is displaying its folders under the Account’s Inbox; the other “breaks them out” under a globe further down the Mailbox Viewer.
As if that’s not bad enough, Mail.app is also eating his draft and sent messages instead of storing them in one of his two (!) Sent folders.
Abstruse error messages in the Console only add insult to injury.
Enough’s enough. It’s good-bye to Mail.app as far as Jon is concerned:
So I guess I’ll be migrating to Thunderbird once I get a free couple days to export all my mail and regenerate my IMAP mailbox. If anyone has any hints about migration or using Thunderbird, I’d like to hear them.
Luckily for him, Derik DeLong from MacUser posted all the answers in a comment to Jon’s post.
Some of his problems can be fixed by setting the right IMAP path prefix for his email provider (More on this in a post and comments on Joseph Scott’s blog).
The rest can be fixed by using the Mailbox -> Use This Mailbox For… menu option to set the folders that Mail uses for its Draft, Sent, Trash and Junk mailboxes (See Apple’s technote on this for more).
