The short answer
No. Your data. Shrink it from its app; don’t delete the folder.
What is it?
Outlook for Mac’s local database: a copy of the mail, attachments, calendars and contacts of each account, in Outlook 15 Profiles inside the Office group container. With large mailboxes it can reach tens of GB.
Your local copy of mail, calendars and attachments. Never deleted by MoreRoom.
What happens if you delete it?
For Microsoft 365, Exchange and IMAP accounts the data downloads again from the server, which takes time. Anything stored only on this Mac (On My Computer folders, imported archives, local calendars) is lost.
How to remove it properly
Do not delete it in Finder. Reduce it from Outlook: empty Deleted Items and Junk, delete or archive large old messages, and remove accounts you no longer use. In legacy Outlook, Tools › Export saves an .olm archive you can keep elsewhere.
From the app itself: Outlook > Settings > Accounts: limit how much mail is kept offline, or archive old mail.
Before you delete it
Back up the profile before any repair or reset; Microsoft’s Outlook Profile Manager is the supported way to start a fresh profile.
How MoreRoom helps
MoreRoom recognises this as your data and never suggests deleting it. It shows how much space it takes, so you can shrink it from its own app.
Frequently asked questions
Can I delete Outlook 15 Profiles to free up space on Mac?
No. Your data. Shrink it from its app; don’t delete the folder. For Microsoft 365, Exchange and IMAP accounts the data downloads again from the server, which takes time. Anything stored only on this Mac (On My Computer folders, imported archives, local calendars) is lost.
Will Outlook mailboxes come back after I delete it?
No. For Microsoft 365, Exchange and IMAP accounts the data downloads again from the server, which takes time. Anything stored only on this Mac (On My Computer folders, imported archives, local calendars) is lost.
How do I remove Outlook mailboxes properly?
Do not delete it in Finder. Reduce it from Outlook: empty Deleted Items and Junk, delete or archive large old messages, and remove accounts you no longer use. In legacy Outlook, Tools › Export saves an .olm archive you can keep elsewhere.