Microsoft has released security updates for vulnerabilities found in:
Exchange Server 2013
Exchange Server 2016
Exchange Server 2019
These updates are available for the following specific...
Updated Jan 12, 2022
Version 17.0
Blog Post
The_Exchange_Team We were Exchange 2016 CU 20 Hybrid mode with all mailboxes on-premise.
To install this security patch, applied CU 22 in one PROD server and DR servers.
Since after applying security update in the PROD server, many users reported Outlook connectivity issues. Whenever they open Outlook for first time, it takes very long time to connect and always shows Trying to connect and Retrieving Files from mail.domain.com. Intermittently Outlook disconnects and shows Tring to connect.
OWA working fine for same users. I checked Server logs and no errors there.
Once I put the updated server to maintenance mode all clients are back to normal.
Any body else faced this issue? Please advise.
Thanks