PowerShell command to delete items in specific mailbox folder in M365 Exchange Online

Question

Hello,

I 've an issue due to so many email items (over 700,000 items) in outbox and couldn't see in outlook desktop app and OWA. Although tried to delete with retention policy, those items are not reducing for over a month. Therefore, I would like to get PowerShell command to delete those items ( with date / time range) if possible. Screen Shot is added below for your reference.

Best Regards,

Kay Zin

Answer 1

Retention policies should be the best solution here, have you done some troubleshooting on that part?

PowerShell on its own won't help you, as Microsoft removed the Search-Mailbox cmdlet a while back. The "alternative" is inadequate for such scenarios, and won't get you anywhere, but for the sake of completeness, here it is: https://learn.microsoft.com/en-us/purview/ediscovery-search-for-and-delete-email-messages

On the positive side, New-ComplianceSearch/Action does allow you to target specific folders. And you can indeed script a loop that deletes items at batches of 10... it's just slow and annoying. Here's a sample script just in case: https://practical365.com/compliance-search-purge/

Instead, I would suggest you use an EWS-based or Graph API based script. This one is a good starting point: https://github.com/David-Barrett-MS/PowerShell-EWS-Scripts/wiki/Merge-MailboxFolders.ps1