That’s why it’s a good idea to turn on AutoArchive because it will take care of it automatically without any intervention. It’s also worth noting that you have to do this for each mailbox you have setup in Outlook. Also, make sure to empty out the deleted items folder afterwards as that still takes up space. I would check the mailbox size and if it’s anything over 500 MB, you should turn on AutoArchive or delete any emails that are taking up a large amount of space.
You’ll see several options as shown below. Click on File and then click on Tools and then Mailbox Cleanup.
