Office 365 for Mac Outlook and hard drive storage

Get rid of CleanMyMac before you destroy your Outlook database, or the Mac in general.

Outlook does NOT need "cleaning". This isn't Entourage, or the version of Outlook in 2011 where it was required to use the Database Utility to actually get deleted items out of the database.

In Office 2016, 2019 and 365, you simply empty the Trash folder. That's it. Any emails and attachments associated with them are removed from the drive.

What it sounds like your Mac is doing is re-downloading everything from the mail server after you clear your account profile.

If this is an IMAP account, stop doing that. Every time you dump the folder, both Outlook and the server think you've never downloaded any of that data before and retrieves it again.

In Outlook's account preferences, click on the Advanced button. Make sure the Sync checkbox is on. The default, and minimum time is 2 minutes. That way, when you clear the Trash folder in Outlook, within 2 minutes, they will also be removed from the server so you don't have them appear in Outlook again.

If you're using a POP account, once again check the preferences and make sure the check box to save a copy on the server is off.

Uninstall CleanMyMac

Dean Conrad wrote:

Lets forget I said Clean My Mac.

Can't forget it. It may be the cause of your issues. Unless you are willing to do as suggested it will be hard to get help.