Released: July 2021 Exchange Server Security Updates

LukasSMSFT 

I need to understand prior we take our decision for CU update. We are at CU 19 and looking to apply July SU's which we know are only applicable to CU20 and CU 21.

We currently do have third party applications which have not yet announced support for CU 21 and we have registered support cases with them for a time line.

My point is if we go for CU 20 and apply July SU's then according t this article

https://techcommunity.microsoft.com/t5/exchange-team-blog/exchange-server-2016-and-the-end-of-mainstream-support/bc-p/2590306#M31012

only CU 21 will get any future security updates, so should we target 21 or go with CU 20, because not looking to perform another CU update in few days time and again, hence looking for advise.

Can we have at least support end date for CU20 clearly? As per documentation (n-1) rule, CU20 was released on March 16th and CU 21 released on June 29th , so CU 20 will be supported till 29th September 2021, please assist if this is correct to help take a decision, it will be much helpful to go ahead for CU 20 as for 21 we need to wait for third party support announcements