It is possible that for some reason a corruption has occurred in your email or pehaps there may be some malicous script in the message which is causing an illegal operation, forcing Mail has quit. Don't attempt to open up the email. Simply drag the un-opened email to your Trash, located in the mailbox drawer. Then go the Mailbox drawer and click on "Delete Deleted Mail" Hopefully this will stop the problem from re-ocurring.
Here is a post on cleaning up Mac Mail and in particular the sql database that Mail runs on:
So how does this help us. Well as Mail uses sqllite to manage it mail, you can use the Vacuum command to clean up the mail database. Using the following command:
You’ll need to issue the following command in Terminal.app:
sqlite3 ~/Library/Mail/V2/MailData/Envelope\ Index vacuum;
That command will work on OS X Lion and Mountain Lion. The command for Snow Leopard is:
/usr/bin/sqlite3 ~/Library/Mail/Envelope\ Index vacuum;
Let me know if it makes a difference to your performance especially of you have had problems in the past.
- See more at: http://danlobo.co.uk/article/speeding-mac-mail#sthash.khy2WmSS.dpuf
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