Tag Archives: Coexistence

Exchange 2013 Cumulative Update 11 – Install it or not?

On December 15, 2015 Microsoft has released Cumulative Update 11 (CU11) for Exchange Server 2013. Okay, I’m a little late with this one, but I wanted to wait some time to see what would happen with this CU….

Note. You can download Exchange 2013 CU11 at https://www.microsoft.com/en-us/download/details.aspx?id=50366, the accompanying UM Language Pack files can be downloaded from https://www.microsoft.com/en-us/download/details.aspx?id=50365 and this is the office Microsoft announcement: https://support.microsoft.com/en-us/kb/3099522. But please, read on before starting to download and install Exchange 2013 CU11.

Now, about this CU….. Microsoft introduced a new feature in CU11 called Mailbox Anchoring. This means that an Exchange Management Shell will no longer connect to the Exchange 2013 server you’re logged on to, but it will be proxied to the Exchange server hosting your current Mailbox. This can be challenging in a mixed environment.

Continue reading Exchange 2013 Cumulative Update 11 – Install it or not?

Exchange 2013 CU10

Microsoft silently released Exchange 2013 CU10 on September 15th 2015, right on track with their quarterly cadence, and as expected. There are no new features in this Cumulative Update, but besides a lot of hotfixes there’s also a change to RBAC which require changes to the Configuration Partition in Active Directory.

So, no changes to the Active Directory Schema, but you have to run Setup.exe /PrepareAD /IAcceptExchangeServerLicenseTerms before you start the actual setup. Please note that you have to do this, even if you run the GUI version of setup. If you omit this step the changes won’t be applied to Active Directory. As a result, the RBAC changes might not be available after your upgrade. A similar issue happened with CU9 as written down in this blog post MessageCopyForSentAsEnabled and MessageCopyForSendOnBehalfEnabled not available in CU9.

Before installing Exchange 2013 CU10 in your production environment I recommend testing it thoroughly in a lab environment. The last couple of CU’s have been pretty successful without too many issues, but there might be specific issues in your own organization that Microsoft is unaware of.

When upgrading DAG members please remember you disable all the Exchange server components as explained in my blog about deploying Exchange 2013 CU9.

You can download CU10 here, and the CU10 Language packs here. A complete list of issues resolved can be found in Knowledge Base Article KB3078678.

At the same time Microsoft released released Exchange Server 2010 Service Pack 3 Update Rollup 11 (KB3078674).

When Exchange 2016 is released in the (near) future, you will need Exchange 2013 CU10 or Exchange Server 2010 SP3 Update Rollup 11 for coexistence. This will be hardcoded in the product, so if you’re planning to deploy Exchange 2016 in the future you have to install these version.

Also, when you’re running an Exchange 2013 Hybrid scenario with Office 365 you have to use the latest version, so in this case Exchange 2013 CU10 is mandatory.

Exchange 2013 coexistence, EAC and ECP

When you introduce Exchange 2013 into an existing Exchange 2010 environment and you want to open the Exchange Admin Center (using https://localhost/ecp or using https://webmail.contoso.com/ecp) it ‘fails’ and it opens the Exchange 2010 ECP instead.


This is caused by the fact that the administrator mailbox is still on Exchange 2010 and the ECP is tied to the administrator mailbox. You can move the mailbox to Exchange 2013 but instead you can also add the suffix /?ExchClientVer=15, like this https://localhost/ecp/?ExchClientVer=15

This will open the Exchange Admin Center in Exchange 2013 while the administrator mailbox is still on Exchange 2010: