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macrumors regular
Original poster
Oct 4, 2015

running OS X 10.12.6 - MacBook pro

mac mail has all of a sudden become really slow and keeps crashing. Im getting the spinning beach ball all the time, it keeps lagging, like when i type an email nothing appears for 10 seconds, then it catches up with itself all of a sudden.

Any ideas on how to fix this? Ive tried restarting my mbp but its still the same.



macrumors 6502a
Apr 26, 2011
Do you have messages stored locally in Mail under "On My Mac"? Do you have any POP accounts. I suggest when setting backup you create your accounts as IMAP.

Quit Mail. Go into your User's Library and rename Mail folder to MailXXX.
While in your User's Library, go to Containers and delete
In System Preferences > Internet Accounts, uncheck mail for each account.
Log out under the Apple in the Menu bar.
Log in
Go to System Preferences > Internet Accounts and check Mail for your main account. Best to do one account at a time.
Open Mail. It should create a new Mail folder in your User's Library.
Once you are satisfied with performance, add back your other accounts.
At this time you can import the "On My Mac" local folders from the MailXXX or Time Machine backup.
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