Fixing Mail.app as it pertains to IMAP and gmail
I am in the process of making gmail my One and Only Mail Database. My first tentative steps showed that gmail filters duplicate emails, which is great, because I have multiple copies of several hundred emails, thanks to POP. Naively, I just started dragging emails from my other Inboxes to my gmail/IMAP/personal mail Inbox and letting the messages synchronize on the gmail server. My goal was to make my other Mail.app accounts empty so I could disable them. This worked well for a while, but for most of today, Mail.app has been telling me this:
Mail has undone actions on some messages so that you can redo the actions while online. Mail has saved other messages in mailbox “INBOX” in “On My Mac” so that you can complete the actions while online. Additional information: The attempt to read data from the server “imap.gmail.com” failed.
I read an article or two and figured I’d overburdened my gmail server and it was scolding me by limiting my access for a while. When about eight hours passed without any change, I knew I had a problem, and that problem was the same email over and over again. Something about embroidery of all things. Each time the message popped up in my “On my Mac” INBOX, I moved it to Trash, then erased deleted messages… nothing worked. Finally, out of desperation, I simply pasted the entire message—you can see it’s quite long—into Google.
The advice there, however, didn’t impress me. I might not be a Mail.app developer, but I imagine that if I delete my entire offline cache, I’ll lose all the emails I moved into my gmail/IMAP/personal mail inbox. That would be bad, considering it’s about 10000 messages, many of which matter to me. I thought I should investigate, and fortunately, it wasn’t too hard to figure out what to do.
I went to ~/Library/Mail/IMAP-[myemailaddress]/.OfflineCache and saw about 10000 numbered files. I looked at one of them and saw an email. I figured I could grep to find the offending email, delete it, restart Mail.app, then all would be well. So I did, and so far it is.
To be clear, here is what I did:
$ cd ~/Library/Mail/IMAP-****/.OfflineCache $ ls 1000 1001 1002 1003 1004 1005 1006 1007 1008 1009 1010 1011 1012 1013 1014 1015 1016 1017 1018 1019 1020 1021 1022 1023 1024 1025 1026 1027 1028 1029 .... $ grep -i embroidery * [...Matched email 854....] $ rm 854
That worked great. I hope it helps you, too.