Mail will automatically attempt to reindex your messages if it detects problems with the mailboxes, but sometimes a manual reindex is the best option. Manual reindexing of Mail messages is the only way to go if the application has become so unresponsive it barely works at all, search is not functioning correctly or the app won't launch. If you are still having issues, or Mail fails to launch, you should try a manual reindex. Now that you've completed these steps, work with Mail a little longer. While the process takes place, you may experience system performance lag, as it can consume a lot of system resources and memory.Īnother caveat, if you use IMAP or Exchange with any of the accounts, the process will redownload every message from the server, so you'll use a lot of bandwidth. You must repeat this step for each one of your Mailboxes. If you have a large mailbox, you can expect the process to take a few hours. At the bottom of the pane choose the Rebuild option.
Launch Mail, select one of your mailboxes and click on the Mailbox menu. Rebuilding a Mailbox in Mail sound daunting but it really isn't.