Potential data loss bug in Mail.app; Workaround
Potential data loss bug in Mail.app; Workaround
We are investigating a potentially serious and now confirmed issue with Apple's default Mac OS X e-mail client, Mail.app, that causes loss of sent messages when working with a large volume of e-mail.
MacFixIt reader Ofir Gal writes "IMAP Bug: Sent messages not always copied to server. Occasionally Apple Mail fails to copy a message to designated mailbox on IMAP server after sending it. When using an IMAP account, Mail allows the user, like most IMAP clients, to store sent messages on a designated mailbox on the server. This enables the user to keep a copy of all outgoing messages. This works most of the time, but randomly fails for no apparent reason and without letting the user know. The only way of telling is by checking the contents of the Sent Messages mailbox. Where I had access to server log, it is clear that Mail makes no attempt to copy the message, so it's not a mail server issue.
"Steps to Reproduce: The only way is to send 100s or maybe 1000s of messages while subbed to an IMAP account and selecting a mailbox on the server for outgoing messages. This can probably be scripted.
"Results: Normally Mail sends a message using SMTP and then proceeds to copy it to the IMAP server. Occasionally it fails to do so. Since users don't normally remember each message they send, it's hard to say how often this happens. But probably 1% of the time.
"Notes: For obvious reasons, some users must have a copy of all outgoing messages and have learnt to trust their mail programs to take care of that."
Update: MacFixIt reader Gordie Waddell offers confirmation and some additional information "I experience this as well. I manage all incoming mail for a busy print shop. Sometimes, I am asked if I have forwarded 'that' message to 'whomever,' so I look in my sent folder and it is not there. I re-forward the message, the recipient gets it, but still it is not in my sent folder. The sent folder does work every time if I compose a message and then send it but it fails to copy a message to the sent folder a lot (way more than 1% of the time) whenever I forward a message. [...] I've just learned to live with this behavior."
Workaround: Martin Moore suggests having the sent folder stored locally your computer. While this defeats the purpose of IMAP in some sense, it will allow you to at least have a solid record of sent messages.
This can be accomplished by creating a new folder that is located on your local volume, and then setting a rule in Mail (accessible in the application's preferences panel) that directs all outgoing messages to that folder. Alternatively, you can simply un-check the 'store sent messages on the server' option from within Mail.app preferences under the 'Special Mailboxes' tab.
If you are experiencing a similar issue, please drop us a line at late-breakers@macfixit.com.Resources