Received a call that a VIP user was not receiving emails or able to send. The quick check to confirm how much room was left in the mailbox. With 20% available the assumption is some sort of connectivity issue. Checking the size of the Online Archive revealed that it was full, and the user must have been ignoring warnings.
By default an Online Archive mailbox is limited to 100GB, hitting this limit will prevent sending emails from the user’s mailbox even if it has plenty of room. When we added the license for this we read “autoexpanding” as the default but no, you have to activate it.
There are some downsides to activating autoexpansion:
- you can no longer recover or restore the mailbox if it is made inactive
- you can only use Content Search on the contents
You have two options for enabling:
- Enable for the organization
- Enable for just the user
Enabling for the organization seems like the easy way out however once Autoexpanding Archives and given the limitations you will want to be selective and limit it to super high volume email users.
Powershell>Set-OrganizationConfig -AutoExpandingArchive
Enabling for just the user has additional advantages:
- The user’s existing Archive is expanded from 100GB to 110GB allowing email sending to resume and the warning quota moves from 90GB to 100GB.
- If the primary mailbox is on hold or subject to a retention policy, the recoverable items quota is also increased by 10GB.
Powershell>Enable-Mailbox -AutoExpandingArchive
Until it breaks here is the source documentation https://learn.microsoft.com/en-us/purview/enable-autoexpanding-archiving