Enable archive mailboxes for Microsoft 365

What is an archive mailbox?

Email archiving in Microsoft 365 (also called In-Place Archiving) provides users with more mailbox storage space. For more information, see Learn about archive mailboxes.

An archive mailbox is like an extra storage space for your emails in Microsoft Exchange Online (used with Outlook, Microsoft 365, etc.). It's often called "In-Place Archive".

When it's enabled for a user, older emails that meet certain rules (called archive policies) are automatically moved from the primary mailbox to the archive mailbox. This helps keep the main mailbox cleaner and can help with performance or compliance.

What does the default archive policy do?

By default:

• Emails that are 2 years old or older (from the date they were sent or created) are moved to the archive mailbox.

• This is done automatically, based on a policy that’s already applied to most Exchange Online mailboxes.

Example:

Let’s say a user receives or writes an email on April 10, 2023. With the default policy:

• That email will stay in the main mailbox until April 10, 2025.

• After that, it will be automatically moved to the archive mailbox.

When does this happen?

This happens after you enable the archive mailbox for that user. If the archive isn't enabled, no automatic move will occur, even if the policy exists.

How to enable an archive mailbox

1. Sign in to the Exchange admin center (EAC) and navigate to Recipients > Mailboxes.

2. In the list of mailboxes, select the user to enable their mailbox for archive.

3. In the flyout pane, select Others, and under Mailbox archive, select Manage mailbox archive:

Manage mailbox archive for a selected user.

1. On the Manage mailbox archive pane, turn on Mailbox archive, and then Save.

It might take a few moments to create the archive mailbox. When it's created, Active is displayed in the Archive status column for the selected user, although you might need to refresh the page to see the change of status.

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REFERENCES

• https://learn.microsoft.com/en-us/purview/enable-archive-mailboxes