In Leopard, when you go offline while using Apple’s Mail program with an IMAP account, you may get the following error message, or something similar:
â€œSome actions taken while the account â€œxxxxxxxâ€ was offline could not be completed online.
Mail has undone actions on some messages so that you can redo the actions while online. Mail has saved other messages in mailbox â€œApple Mail To Doâ€ in â€œOn My Macâ€ so that you can complete the actions while online.
Additional information: The IMAP command â€œAPPENDâ€ (to Apple Mail To Do) failed with server error: Invalid mailbox name..â€
And if you click OK enough times, the program crashes.
There are two ways to correct this problem (both ways will preserve your mail settings (you will NOT have to reconfigure your Mail program) and your mail will appear in a few seconds after first opening the Mail program after performing the fix below):
1st Way (easier way)
1. Make sure your Mail program is closed
2. Open Macintosh HD (double-click on it)
3. Select your Home folder (it will be on left nav bar with the picture of a house)
4. On the right side of the window, double-click on the “Library” folder (to open the folder)
5. Double-click on the “Mail” folder
6. Remove (move to the trash) the “IMAPemail@example.com” folder
7. Close everything and open Mail to confirm it has been fixed
Delete all entries in~/Library/Mail/IMAP-email_address@mailserver/.OfflineCache . The folder is actually only accessible in shell since its a hidden directory, so you will need to access it via Terminal. This is for advanced users only, so I won’t bother writing a step-by-step instruction, as those users will know how to do it.