Ich habe wiederholt den Fehler „Account exceeded bandwidth limits. (Failure)“ von Apple Mail bekommen.
Normalerweise sperrt Google dann den Accound für runde 24 h. Wenn Mail dann gleich wieder Amok läuft wird der Account gleich wieder gesperrt. Diese Anleitung hat bei mir funktioniert und das Problem behoben:
(1) If you encounter the „Account exceeded bandwidth limits. (Failure)“ error, then quit Mail.app and leave it closed (or just disable your Gmail IMAP account if you use Mail.app for other accounts as well) for 24 hours so that Google will reset your IMAP bandwidth limit. At this point, if you have Gmail set up with your iPhone or other IMAP clients, it should work there.
(2) Delete the hidden folder „.OfflineCache“ at the following path: „~/Library/Mail/IMAP-@domain.tld@imap.domain.tld/.OfflineCache“* (step-by-step instructions included at end of post in case you don’t know how to do this)
(3) Delete the „Recovered Files“ Mailbox folder at „~/Library/Mail/Mailboxes/Recovered Messages ([Gmail Account Name]).mbox“
(4) Open Mail.app and try to connect to your Gmail account — it should now work.