Exchange Center

Decommissioning the last Exchange server

When you are in an Exchange hybrid configuration and you have migrated the last Mailbox to Office 365, you might wonder what to do with the last (couple of) Exchange server that is still running on-premises. Can you decommission your last Exchange server because all your Mailboxes are in the cloud? From a supportability point of view the answer is still “No, you can’t decommission the last Exchange server because you need it for management purposes” and most customers think this is disappointing. Let me explain why we still need this last Exchange server.

Securing Exchange Servers

Securing Exchange servers is hard. I mean it can be a giant pain sometimes. There are what, hundreds of millions or maybe billions of lines of code running on your Exchange servers, right? It doesn’t take much for a typo to get through and open a vulnerability that can then be exploited opening the most important and valuable data within your organization to all kinds of bad actors.

Exchange on-premises and Microsoft Teams

With the work from home going on due to the COVID-19 crisis there’s an increasing demand for tools like Zoom, Skype for Business and Teams. While Zoom is doing a great job for personal use, I prefer Skype for Business or Microsoft Teams for business use.

Since the early days of Exchange Server, the limits of user mailboxes were strictly regulated. In many Exchange organizations, these quota limits were configured on a mailbox database level and were therefore consistent for all mailboxes stored in the same database. This approach was selected because the existing hard disk space was scarce and expensive in the past.

On December 17, 2019 Microsoft released Exchange 2019 CU4 and Exchange 2016 CU15 as part of their quarterly release cycle. As expected, no new features in these Cumulative Updates. According to the Microsoft vision, if you want the latest and greatest you need Exchange Online, if you’re satisfied with a rock solid on-premises deployment you’re good with these versions. And since Exchange 2013 is out of support, no Cumulative Update for Exchange 2013 is released.

On September 17, 2019 Microsoft released its quarterly updates for Exchange. This time, the updates contain Exchange 2019 Cumulative Update 3 and Exchange 2016 Cumulative Update 14. No updates are released for Exchange 2013 or Exchange 2010.

Over the past 20 years we’ve seen some dramatic changes in Microsoft Exchange Server. Exchange server 2000 was the first version that was using Active Directory, after switching from its own directory that was in Exchange server version 4.0 until version 5.5.

In an earlier blog post I wrote about Autodiscover changes, especially when using Outlook 2016 Click-to-Run.

The virtualized operation of Exchange Server has been a hot topic for discussion ever since the introduction of hypervisor platforms. Often these discussions are very emotional, and the valid arguments rarely heard.

The Exchange Team provides you the Exchange Role Requirements Calculator now for a long time. This tool is still maintained and the preferred one for correct sizing. You can find information on how to use it on this EHLO blog post.