Forum Discussion
Email sent from Shared Mailbox gets stuck in Outbox
Hello, I am working with a client who has a primary and shared mailbox in Outlook. They are using the newest version of classic Outlook desktop app and they have full permissions to the shared ma...
I am having the same issue and seeking a resolution. Like you, I thought I originally resolved this by removing data files and profiles within control panel > mail. I then re-added the primary account including shared mailbox. I was able to send as the shared mailbox for a few hours and prematurely celebrated.
Shortly after, I noticed that items are stuck in the outbox... and even stranger is that even though the profile and data files were removed, the outbox showed items stuck from before the data & profiles were removed. (they were not there when the accounts were re-added, but they came back somehow).
Shortly after, I noticed that items are stuck in the outbox... and even stranger is that even though the profile and data files were removed, the outbox showed items stuck from before the data & profiles were removed. (they were not there when the accounts were re-added, but they came back somehow).
armandsalmon Hey, so we managed to get this resolved using the solution below. Since we applied this, it's been 2 months without issue. I hope this helps you as well.
Resolution
The issue was resolved (with Microsoft support help) by re-applying Full Access permissions and removing shared mailbox Outlook auto-mapping for the affected users and then adding the shared mailbox manually in Outlook. Re-applying permission via Office 365 admin centre didn't have any effect.
- Launch Windows Power Shell as administrator and connect to your Office 365 tenant.
- Run: Remove-MailboxPermission -Identity email address removed for privacy reasons -User email address removed for privacy reasons -AccessRights FullAccess
- Run: Add-MailboxPermission -Identity email address removed for privacy reasons -User email address removed for privacy reasons -AccessRights FullAccess -AutoMapping:$false
- -AutoMapping:$false disables shared mailbox auto-mapping to users' Outlook profiles.
- Wait 30-60 minutes for changes to propagate until shared mailbox disappear from users' Outlook.
- Manually add shared mailbox to users' Outlook: File > Account Settings > Change > More Settings > Advanced > Open these additional mailboxes.
- Try sending email as the shared mailbox by selecting From: address from Online Global Address List (to prevent caching issues).
