CU4 | Jaap Wesselius

On December 17, 2019 Microsoft has released its quarterly updates for Exchange Server:

Exchange 2016 CU15.
Exchange 2019 CU4 (only available via Volume License).

There are a couple of things that are worth noting:

Both Exchange server versions need the .NET Framework 4.8. If you are running an older version of Exchange (much older) consult Michel de Rooij’s blogpost Upgrade Paths for CU’s and .NET.
If you are running an Exchange Hybrid version there’s the n-1 policy. This means your on-premises versions of Exchange should be Exchange 2016 CU14 or Exchange 2019 CU3 at minimum.
There’s an update on the Exchange calculator which is now version 10.3.
There are no schema changes compared to the previous version so there’s no need to run Setup.exe /PrepareSchema. I always recommend running Setup.exe /PrepareAD to make sure any additional features or changes like (for example) RBAC are applied correctly.

So now real new features which is in line with Microsoft’s strategy. If you need the latest and greatest then Exchange Online is the way to go. If you need a stable on-premises environment you’re good with Exchange 2016 or Exchange 2019.

More information

Released: December 2019 Quarterly Exchange Updates
Exchange 2016 CU15 Download: https://www.microsoft.com/en-us/download/details.aspx?id=100780
Exchange 2016 CU15 UM Pack: https://www.microsoft.com/en-us/download/details.aspx?id=100781

On Tuesday december 13, 2016 Microsoft has released its quaterly updates:

and Update Rollups:

Looking at Exchange 2016, what does this CU bring us?

There are minor changes to the user interface of Outlook on the Web or Outlook Web App, whatever you may call it. It’s not that dramatically, the formatting controls have been moved to the bottom of the frame containing the editing pane, as can be seen on the following screenshot.

And finally, there’s support for the .NET Framework 4.6.2. Using .NET Framework 4.6.2 is still optional (but recommended), but the upcoming release in March 2017 (Exchange 2016 CU5) will require the use of .NET Framework 4.6.2.

As you might have noticed, Exchange 2016 CU3 (the previous release) introduced support for Windows Server 2016. This was also announced at the Ignite 2016 in Atlanta. Unfortunately there was a major flaw in Windows 2016 clustering that caused issues with Exchange 2016 in a Database Availability Group configuration. This has now been fixed by the Windows team (KB3206632), and Exchange 2016 again fully supports Windows 2016. The hotfix is mentioned is mandatory, and the setup application does a check for this hotfix.

Exchange 2016 does not introduce any new schema changes, but you may execute setup.exe /prepareAD /IAcceptExchangeServerLicenseTerms to make sure any changes in the configuration partition are applied successfully.

As usual, and especially after the latest issues with Exchange 2016 CU3 and Windows 2016 I strongly encourage everybody to thoroughly test Exchange 2016 CU4 (or any other update that’s needed of course) in your lab environment before bringing it into production!