0

I am facing a problem when a migration process from GSuite led to an unconsistent user's mailbox - migration process stopped several times and finally hit mailbox size limit (100Gb) which is much more than expected (~65Gb).

So the mailbox should be cleaned completely and I would like to perform another kind of migration (not API-based, at least - via IMAP or even PST). The problem is I can't find any solution to empty the mailbox.

What I have tried so far:

  1. Emptying the mailbox with outlook online - folders are empty, but mailbox usage is about 70Gb (this is probably my mistake - see below)
  2. Empty the mailbox using search-mailbox -DelectContent cmdlet - extremely slow, no effect, mailbox usage is about 70Gb
  3. Applying set-mailbox -RetainDeletedItemsFor 0 cmdlet - still no effect.

Is there a way like it was in on-prem exchange - disconnecting a mailbox from user and creating a new one from scratch?

2 Answers 2

2

In Office 365 admin center > USESRS > Active Users > find the user, delete it. It will go to the Deleted Users.

Create a brand new mailbox with exactly the same information for the user

In addition, i found a similar thread for your reference: Wipe Content from an Exchange Online Mailbox

2
  • Is this method effective?
    – Joy Zhang
    Aug 10, 2020 at 7:01
  • Sorry for the late reply but - method with delete/create users won't work - script from the article did the trick but I can't say it is really simple. I mean I experience no problems with powershell but the script generates eceptions, leaves mailbox unerased etc. Anyway, again, it did the trick. Thank you.
    – Cyrill U
    Sep 1, 2020 at 15:23
1

Here's one method of doing it:

Remove the Exchange Online license from the user in question.

Connect to Exchange Online with Powershell.

Run the following command:

Set-User youruser@yourdomain.com -PermanentlyClearPreviousMailboxInfo

Re-assign the Exchange Online license.

This will create a new, empty mailbox for the user in question.

1
  • Seems it isn't working. I removed licenses and ran the command, it did withiut errors. Now, when I add licenses back, I get the same size of mailboxes :(
    – Cyrill U
    Aug 5, 2020 at 9:10

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.