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Free up space with Online Archive in Outlook for Mac

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Hey Insiders! My name is Priya Ganta, and I’m a Program Manager on the Outlook team. I’m excited to share that one of the most-requested Outlook for Mac features is finally here: Online Archive! 

Online Archive for Mac

An Online Archive (also called an archive mailbox) is a place for storing old email messages, freeing up space in your primary mailbox. This archive mailbox appears alongside your primary mailbox, and is accessed the same way that you access your primary mailbox and folders in the new Outlook for Mac.Screenshot showing the Online Archive option in Outlook for Mac

The Online Archive must be enabled for you by your IT department or Microsoft 365 admin. If you’re an admin, please check out Enable archive mailboxes in the compliance center for more information.

NOTE: All Outlook users have an Archive folder as part of your primary mailbox. This is different from the Online Archive, which is a separate mailbox that doesn’t count against the space limits of your primary mailbox.

How it works

If you have a Microsoft 365 account and your IT or Microsoft 365 admin has enabled the archive mailbox, your Online Archive mailbox will appear in your Outlook folder pane.

To use your Online Archive:

  1. Open the new Outlook for Mac.
  2. In the Outlook folder navigation pane, find and click Online Archive.Screenshot showing the expanded Online Archive in Outlook for Mac
  3. Explore your Online Archive folders and messages.

NOTE: Currently, the new Outlook for Mac only supports the Mail module in the Online Archive. If you move folders, calendar items, contacts, tasks, or notes to your archive in Outlook for Windows, you won’t be able to view or access them in the Online Archive on your Mac. 

Tips and tricks

  • For easy access, you can simply drag and drop messages from your primary mailbox into your Online Archive.
  • Your IT or Microsoft 365 administrator sets the archive and retention policies for your entire organization. Archive policies control how long messages are left in an email folder before they’re moved to an archive. Although admins set these policies for the entire organization, you can override the policies in the Outlook Web App to suit your needs. For more information, see Retention and archive policies in Outlook Web App.


In order for your Online Archive mailbox to work with the new Outlook for Mac, your mailbox should be located on a Microsoft 365 server.

Known issues

  • The unread mail count in Online Archive doesn’t sync across different platforms.
  • You can’t successfully send email when attempting Reply, Reply All, or Forward operations from your Online Archive.


This feature is available to Office Insiders running Version 16.54 (Build 21092901) or later on Mac.

Features are released over some time to ensure things are working smoothly. We highlight features that you may not have because they’re slowly releasing to larger numbers of Insiders. Sometimes we remove elements to further improve them based on your feedback. Though this is rare, we also reserve the option to pull a feature entirely out of the product, even if you, as an Insider, have had the opportunity to try it.


We’d love to hear from you! You can submit feedback in Outlook by clicking Help > Contact Support.

Learn what other information you should include in your feedback to ensure it’s actionable and reaches the right people. We’re excited to hear from you!  

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