Why’s my 50 GB mailbox only 25 GB?

2018-01-29 edit-the same principle applies today with the 100GB mailbox limits if your are still seeing 50GB on older mailboxes.


Office 365 recently upgraded all enterprise customers mailboxes from 25 GB to 50 GB, but some users may find that they are still seeing only 25 GB of storage. If you find yourself in this situation, here’s a couple of quick fixes to set your users up for their new massive mailboxes.

Existing Users

If you have existing users whose mailboxes are still showing 25 GB limits, but you’ve been upgraded to the new 50 GB size, you just need to adjust those users. Here’s what you can do.

    1. Confirm that your mailbox databases have been upgraded. They should be by now, but best to make sure before you proceed. Open a remote PowerShell session to Office 365 and run this command
      get-mailboxplan | fl displayName, *quota
      If your quotas still show 25GB limits, open a support case.
    2. Run this command to increase the mailbox quotas for the 50 GB limits
      get-mailbox -resultsize unlimited | set-Mailbox -IssueWarningQuota 48.5GB -ProhibitSendQuota 49GB -ProhibitSendReceiveQuota 50GB
    3. Profit.

New Users

If you want to ensure that new users are automatically provisioned with the 50 GB limits, you want to update your mailbox plan defaults. You will have to do this for each mailbox plan in your tenant.

1. Remote PS to your tenant.

2. Get-MailboxPlan to get the plan(s) in your tenant.

3. Run this command, substituting your plan name. Command is one line that wraps.

set-mailboxplan ExchangeOnlineEnterprise-fdeba728-963d-40df-8ff3-9a6b7a751ab2 -IssueWarningQuota 48.5GB -ProhibitSendQuota 49GB -ProhibitSendReceiveQuota 50GB

4. Rinse and repeat if you have more than one, or you could do a “get-mailboxplan | set-mailboxplan…” to nail them all at once, as long as you don’t mind getting an error for any plans, like K, that cannot go that high. It won’t hurt anything to do it that way, but some folks hate to see red text.

And with that, you have some really big mailboxes for all your users. They won’t need to delete anything for years to come, unless of course they use their mailbox as a file system, and subscribe to every DL and newsfeed they’ve ever seen. Even then, if they want it all, they can have it all!

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