User is unable to send as shared mailbox

Question

Hello All,

One of the user reported that he is unable to send mails from shared mailbox with send as permission,

He is outlook client application and we suggested to check in web.

From web its working but from Outlook app it's not working

Please suggest what could be the suggested fix for this.

Answer 1

Hello, @Mani,

Welcome to the Microsoft Q&A platform!

Based on your description, the issue might be related to the Outlook client application not properly recognizing the "Send As" permissions.

Here are a few steps you can try to resolve this:

1.Clear the Auto-Complete Cache: Outdated cached information can cause issues. In the new email message in Outlook, click on the "From" field, then select "Other Email Address". In the "Send From Other E-mail Address" window, click "From" again, change the address book to the Global Address List (GAL), and select the user to whose mailbox you were granted "Send As" permissions.

For reference, please click on A user who has Send As permission can't send email messages as another user account in Outlook in Office 365 - Microsoft Support.

2.Update the Offline Address Book: Outlook client needs to update its address book to recognize new permissions. You can do this by going to Send/Receive > Send/Receive Groups > Download Address Book and then clicking OK.

3.Reassign Permissions: Reassign the "Send As" permissions using PowerShell to ensure they are correctly applied. Here’s a basic command to do this:

Add-RecipientPermission -Identity "SharedMailbox" -Trustee "User" -AccessRights SendAs

4.Profile Reconfiguration: Reconfiguring the Outlook profile sometimes can help. You can do this by going to Control Panel > Mail > Show Profiles and then creating a new profile.
5.Repair Office: Try repairing the Office installation. Go to "Control Panel > Programs and Features", select Microsoft Office, and choose "Change" then "Repair".

If these steps don't resolve the issue, it might be helpful to capture any error messages or logs when the user attempts to send an email from the Outlook client. This information can provide more insight into the root cause of the problem.

Should you need more help on this, you can feel free to post back. 

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If the answer is helpful, please click on “Accept answer” as it could help other members of the Microsoft Q&A community who have similar questions and are looking for solutions.

Thank you for your support and understanding.

Best Wishes,

Alex Zhang