u/titsablast

Hello,

I have many shared mailboxes that have enabled MessageCopyForSentAsEnabled and MessageCopyForSendOnBehalfEnabled.

Since a maintenance a few days ago everyone that sends an e-mail as one of those mailboxes to external adresses gets that e-mail attached to an e-mail to the inbox of that shared mailbox with this text:

The attached message was sent by a member of this shared mailbox. Usually, it would appear in Sent Items, but your service is currently being upgraded. Things will be back to normal after the upgrade.

It's still also still stored in Sent Items of the personal and the shared mailbox successfully.

All mailboxes are in Ex Online, but Ex OnPrem is used for incoming/outgoing mail with Central Transport enabled with Hybrid Wizard.

This inbox-e-mail only happens when sent to external addresses, not internal mailboxes.

Background to the maintenance:

Single Exchange SE installed June updates by WSUS

* Exchange KB5904139

* Windows Server 2022 KB5094128

A colleague told me it went like this:

* Updates were installed. Afterwards VM was rebootet.

* Windows CU got rolled back during windows server reboot.

* When Windows finished booting, many services were disabled: Exchange Services, WMI, Remote Registry. He enabled them and started them.

* Then the Windows CU was installed once again (Exchange SU already reported as installed successfully).

* Server was rebooted. This time all seems fine, mail flow worked.

I checked component states, HealthChecker-Script and Logs like C:\ExchangeSetupLogs\ServiceControl.log. So far I can't find anything obvious that looks wrong with Exchange.

Anyone has suggestions, seen this error?

Currently I'm thinking uninstall and reinstall Exchange SU might be an option to try?