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Released: March 2024 Exchange Server Security Updates

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The_Exchange_Team
Platinum Contributor
Mar 12, 2024
Update 4/23/2024: We have now released April 2024 Hotfix Updates which address known issues in March 2024 SU updates. Microsoft has released Security Updates (SUs) for vulnerabilities found in: ...
Updated Apr 23, 2024
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Johnny_Yao_Taiwan's avatar
Johnny_Yao_Taiwan
Brass Contributor
Mar 15, 2024
The_Exchange_Team 

That is correct. Both the unread email and the search issue is specific to on-premises hosted mailboxes (and have nothing to do with Exchange Online hosted mailboxes). But note that not all on-prem environments will experience both (or either) of those issues. This is proving tricky to nail down. 

FYI
It also impacted to the Exchange Online users. 

Yesterday I've done fully testing on my Exchange 2016 Prod & Lab enviroment which are both built with hybrid mode. 

I can confimred that unread issue also happened when Exchange Online users received email from onprem sender and vice versa. 

 

So I guess the main reason is something change on the transport agent layer? But I didn't found anything different from message header. 

Figrure - a EXO user recevied emails from onprem still stay on unread status after opened.