Apple Mail gets stuck in a ‘recovered mail’ loop

I had a call today from a client who was having trouble with Apple Mail. Specifically, there was a 25mb email sent to him by a family member that Mail was continually trying to ‘recover’ and send up to his Google Apps mail account. After a bit of googling, the answer was pretty easy, though asking someone to use the ‘rm’ command who’s never used the Terminal.app was a little concerning :)

# Close Mail.
# Open a new terminal window and paste the following:
# ls -la
# Then replace ‘email@domain.com’ with the one that matches the account that’s having issues
# rm ~/Library/Mail/email@domain.com/.OfflineCache

That should fix it.