I Use Outlook For Mac and I Switched to New Outlook that Deleted All of my .PST and .OLM Backup Files

Question

I am very concerned about the New Outlook for Mac now.

I am in a situation where I am running a company and it is critical that our Outlook is backed up to .pst and .olm files.

In changing to the New Outlook, I was asked if I wanted to delete my transferred emails and files to save space. I foolishly pressed yes. This deleted all of my backup .pst and .olm files. They are gone.

Our company is changing to a new ISP and we must migrate our email from the old ISP. I can now not backup all of my email in the new Outlook to .pst or .olm files.

When I switch back to Classic Outlook to do this, my emails and folders in New Outlook are NOT available there!

Is there a workaround to this problem please??

Answer 1

Dear @Mark Arnold,

Welcome to Microsoft Q&A Forum!

First of all, I would like to let you know that this is a peer-to-peer forum where Microsoft Q&A moderators support you based on user-to-user experiences so that we cannot recover data for you or directly access to your environment to check it due to security protocols. Even Microsoft Support team does not have data recovery service. However, I'm still here to give you some insights to see if they can improve this issue in somehow for you.

Thank you for the detailed explanation. Based on Microsoft’s documentation, I want to clarify how data works between Legacy (Classic) Outlook for Mac and New Outlook for Mac, and what can and cannot be recovered.

1.Difference between server (cloud) data and local data:

• Server‑based mail (cloud): If your account is Exchange / Microsoft 365 / Outlook.com / IMAP, your emails are stored on the mail server and are synchronized to Outlook. This data should also be visible in Outlook on the web when you sign in.
• Local‑only data: Items stored under “On My Computer” folders, and data contained in .OLM or .PST files, exist only on the Mac and are not synchronized to any server.

Microsoft explains this clearly in About On My Computer folders in Outlook for Mac: items in On My Computer are saved only on the local device and are not available on the server or other clients. Please see this article: About On My Computer folders in Outlook for Mac

2.New Outlook for Mac does not import or export .PST / .OLM:

• Importing and exporting .PST and .OLM files is only supported in Legacy Outlook for Mac.
• New Outlook for Mac does not import local .PST or .OLM files, and it does not support file‑based backups.

This is explicitly stated in Import email messages, contacts, and other items into Outlook for Mac, which notes that this feature is only available in Legacy Outlook for Mac, and imported items appear under On My Computer.

3.About the deletion of local backup files:

• When you switched to New Outlook for Mac and chose the option to delete transferred data to save space, Outlook removed local‑only data, including any .PST / .OLM backups that were stored on the Mac.
• Because those files are not stored on the mail server, Outlook itself has no way to recover them.

The only possible recovery path is restoring the deleted files from a macOS Time Machine or disk backup that was created before the deletion. If no Mac backup exists, Outlook cannot restore deleted local archive files.

4.Important checks for you:

Please check the following to confirm what is still safely stored on the server:

• Sign in to Outlook on the web at https://outlook.office.com
• If your emails appear there, they are safely stored in the cloud.

In New Outlook for Mac:

• Confirm whether you see your folders and messages that match Outlook on the web.
• New Outlook typically does not show “On My Computer” folders. Please see again the second link above for this feature.

In Legacy (Classic) Outlook for Mac:

• Check whether any “On My Computer” folders still exist.
• If they are gone, Outlook itself cannot rebuild them.

Also, if you truly used Time Machine to back up before, check it as well. If not, I sincerely apologize for it.

I hope this information can give you some insights and please let me know how things go on your side as your update can also assist others in the community who may be facing the same issue.

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