5.7.60 SMTP; Client does not have permissions to send as this sender.

Question

I've set up a new Exchange Server 2019, but some users are encountering the error: "5.7.60 SMTP; Client does not have permissions to send as this sender." I reset the security settings to default in Active Directory for the specific user. Initially, it worked fine, but after a few minutes, the permissions were revoked again. I've also added "Send As" and "Receive As" permissions in the advanced security settings, which works temporarily but eventually reverts. What could be the proper solution for this user?

Answer 1

Hi @Parsian02 ,

Welcome to the Microsoft Q&A platform!

Based on your description, the error message "5.7.60 SMTP; The client does not have permission to send as this sender" usually indicates a permissions issue related to the "Send As" permission in Exchange Server 2019. Here are a few steps you can take to troubleshoot and possibly resolve this issue:

1. Make sure the "Send As" permission is correctly applied to the user. You can do this using the Exchange Management Shell:

Add-ADPermission -Identity "Mailbox" -User "User" -ExtendedRights "Send As" 

2. Sometimes, conflicting permissions can cause problems. Make sure that no deny permissions are set for the user.
3. Active Directory replication delays may cause permissions to be temporarily restored. Make sure the changes have been replicated to all domain controllers.
4. If email address policies are being applied, they may overwrite permissions. Check the policies and make sure they do not affect the "Send As" permission.
5. If you are using managed service accounts, make sure they have the necessary permissions and have not been reset by the system.
6. If the user belongs to a group with "Send As" permissions, make sure the group membership has not changed.
7. Run the Exchange Best Practices Analyzer to check for any misconfigurations.
8. Make sure your Exchange server is updated to the latest cumulative updates and patches.

If the problem persists after trying these steps, it may help to enable diagnostic logging for the MSExchangeIS service to collect more details about the permission changes.

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Please feel free to contact me for any updates. And if this helps, don't forget to mark it as an answer.

Best,

Jake Zhang