Outlook mailbox full but is not? Here’s the fix

Last Updated on April 20, 2017 by Dave Farquhar

So your Outlook mailbox says it’s full, but is not? If you have a problem with phantom e-mail in Outlook, resulting in an Outlook mailbox full even after deleting a pile of messages, you can fix it. I did, and it was chewing up all my Exchange server space. Here’s how I fixed it.

I run Outlook connected to an Exchange server at work, and I’m constantly running out of mailbox space. When I go into Mailbox Cleanup, click View Mailbox size, and click on the Server Data tab, I see lots of space in my outbox–54 megabytes in this case–with no way to clean it out from inside Outlook. Yet when I look in my Outbox, there’s nothing in it. I’ve run Scanpst, which is the usual cure for Outlook maladies, but that didn’t eliminate the invisible messages either.

When the amount of space you can see doesn’t match the amount of space you’re actually using, go into Outlook Web Access and empty it.

From inside Outlook Web Access, I could see 8 large e-mail messages stuck in my Outbox. I could right-click on it and select Empty Folder. That moved them to Deleted Items. So then I right-clicked Deleted Items and selected Empty Deleted Items, and they disappeared.

Then I went back into Outlook and ran Mailbox Cleanup again. The phantom 54 megabytes of stuff that was taking up so much space in my outbox was gone. All that remained was the 22 or so megabytes of real messages.

It’s going to be weird not having to go through the daily ritual of dealing with automated Your Mailbox is Almost Full and Your Mailbox is Full messages.

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