mail.app
Is it possible to exclude a specific mailbox from the "Inbox" view in Mail.app?
I got 3 mailboxes in mail.app, 2 of them are mail accounts for normal mail communication, 1 is used for receiving mails from senders which sometimes send to much mail (newsletters etc.). The problem that occurs is that all the newsletter mails show up in the "Inbox" view preventing me to see the mails from the other mailboxes.
Well, in Mail 4.5 (on Snow Leopard) it's easy: add a condition "Message is in Mailbox" to your smart mailbox's filter. In my case, that "Gmail" mailbox is a sub-box of the (unified) Inbox.
I had a similar problem in Mail on Mountain Lion, where attachments did not show up for a message. When looking at the raw source (⌘⎇U) of the message, I also found that headers of the message were missing.
I managed to fix the issue by selecting the mailbox containing the broken email, and then using the "Rebuild" command from the "Mailbox" menu. After a short time, my emails reappeared, complete with attachments.
Best Answer
Update - Mail has a filter option to the right of the 'sort by' at the top of the email column where you can choose which mailboxes, or to only show unread, etc.