Exchange 2016 and 2019 End of Life Preparation Guide
In a few months, Exchange 2016 and 2019 end of life will occur on the same day. October 14 2025 to be exact. On that day both these Microsoft on-premise server editions which have served their users long and faithfully for many years will seize to receive official support. However, like all good things, their time is now nearing the end.
So if your organization still conducts day-to-day business operations on any of these on-premises systems you must upgrade ASAP.
Don’t worry as neither are you alone nor has such an EOL happened for the first time. Through this write-up, we will condense down our years of experience in helping organizations like yours to navigate the end of support scenarios with minimum disruptions.
Let us start by understanding what it means when a service undergoes EOL.
What Does Microsoft Mean by Announcing Exchange 2016 and 2019 End of Life?
In software terminology, End of Life, or EOL for short refers to the phase in which the software manufacturer (which in this case is Microsoft) ceases to provide any further security or functionality updates.
It does not mean that your server will stop working so users can continue to send and receive messages like normal.
Moreover, this is not a new development as both Exchange 2016 and 2019 follow Microsoft’s Fixed Lifecycle Policy. With minor differences.
For the Exchange 2016 edition, the official documentation states that the mainstream support ended on the 13th of October 2020 (more than 5 years ago) and since then it has been on Extended support which will also end on 14th October 2025.
Whereas for Exchange Server 2019, the timeline is as follows the mainstream support ended on January 9, 2024, and its extended support will also end on the same date i.e. 14th October 2025.
Why Organizations Should Not Keep Using Exchange Servers Beyond their EOL Date
Once the EOL date passes both versions no longer receive any official technical support.
Cybercriminals actively hunt for such unpatched systems, and Exchange servers, with all that sensitive email data, are incredibly valuable targets. There have been countless stories online, from admins who’ve been hit by ransomware multiple times after their Exchange Server’s EOL. Taking the Exchange 2016 and 2019 end of life lightly is like ignoring a digital time bomb
A dangerous trend that exacerbates the issue is overconfidence in in-house abilities to “patch things up” after support ends. Organizations might think their IT team can handle any security issues, but Exchange is incredibly complex. Prone to Exchange Server database corruption. Trying to manage vulnerabilities without official patches is like trying to perform surgery with a butter knife – it’s almost guaranteed to make things worse, leading to far greater costs and damage than a proper migration.
Moreover, If you’re in an industry with data protection regulations like HIPAA (for healthcare) or GDPR (in Europe), running unsupported software is a direct violation. We’re talking about potentially massive fines and legal repercussions. These regulations don’t say “Don’t run Exchange 2016,” but they do require you to maintain “reasonable and appropriate” security measures, and unpatched software is anything but that.
All these point to a clear answer which is that upgradation is a must.
Migration Path Options Available Before Exchange 2016 and 2019 End of Life Occurs
These options will also be available after the EOL date. For the majority of the users, there are two straight ways they can continue to securely use Exchange Server services.
Either switch to the M365 cloud right now from whatever Exchange Server you are running or update to the latest Exchange Server 2019’s CU 15 update and wait for the Exchange Server SE edition.
Moreover, you might start to understand that the steps you take to get to the end state depend on what server edition you are currently on. Let us first explain the two methods stating what we believe is the better option.
Take your Exchange Server Online to Microsoft 365 Cloud
If you choose this you enjoy the following benefits.
Cost Reduction: Organizations can do away with all the hefty budget allocated for on-site hardware purchases.
Always Up-to-Date: All server-side software updations (feature and security) happen under the hood with 0 intervention.
Better Scalability: Organizations pay for only the amount of service they use no more no less. So this is another form of cost saving as during non-peak hours they no longer have to worry about keeping the server online essentially adding electricity bills for an idle server.
Moreover in the opposite case too where all of a sudden the demand peaks admins no longer have to make an emergency purchase or shut down some services as the cloud will expand to balance it automatically.
Remote Accessibility: If after Exchange 2016 and 2019 end of life you go to the cloud your users will have round-the-clock accessibility from any remote corner of the world. No longer will the admin have to apply firewall entry points for personal user devices all this mistaken care by the service provider which in this case is Microsoft.
However, there are still a few considerations that may prevent certain organizations from migrating Exchange 2019 to Office 365 cloud.
Subscription fees are applied on a per-user basis. If not managed carefully can quickly overflow.
Internet reliance becomes mandatory. This comes as no surprise all servers (and the underlying data) are now located offsite which is only accessible via the network.
Beat Exchange 2016 and 2019 End of Life By Upgrading to Exchange Server Subscription Edition (SE)
This is a new type of on-premises option available for those who wish to have greater control of the hardware. However, as mentioned before upgrading to this is very different for 2016 and 2019 users.
Note that this service is not out yet and Microsoft will release the Exchange Server Subscription Edition (SE) in the second half of 2025. Organizations that want to go for this route must prepare their existing infra nonetheless.
Exchange 2019:
If you have installed and updated the Exchange 2019 CU15 released on 10 February 2025 then all you have to do is wait.
Once the SE edition comes out you can install it like any other regular Cumulative Update (CU).
For Exchange 2016 Users:
The steps get a bit complicated as there is no direct upgrade, the entire process is divided in two parts.
First, migrate to Exchange 2019: This is a full-blown migration, just like moving to the cloud (but to another on-premises server).
Then Upgrade to Exchange SE: Once you’re finally in 2019, you can do the in-place upgrade.
As you still have time before the SE server releases we recommend that you make the switch to the 2019 edition as fast as possible.
If during Exchange 2016 and 2019 end of life you are upgrading to SE keep in mind:
You retain all ongoing costs. Organizations will still have to pay for the hardware, maintenance, and power.
Unlike the previous Exchange Servers which operated on a single-cost perpetual-use model, the new one is named Subscription Edition. So you will have to pay fees at regular intervals and require Software Assurance for CALs.
Updates will be free but installation and deployment will be the admin’s responsibility.
Once your migration path is confirmed you can rely on an automated utility for help.
Migrate Professionally Before Exchange 2016 and 2019 End of Life
The SysTools Exchange to Office 365 Migration tool can safely deposit all critical user mailbox data to the Exchange Online environment.
With the ability to filter the workload, time period, and user accounts as well as select how many accounts will migrate simultaneously and in which order this tool has all that an admin would want.
In case your organization has to retain an on-premise setup and is operating an Exchange Server 2016 or older edition then you can utilize the sister tool instead. The Exchange On-Premise to Exchange Server provides excellent support to all those who want to make their self-managed systems ready for the Exchange Server SE (subscription edition) by upgrading to the 2019 edition with CU 15.
To use the tool follow these steps
Step 1. Install a copy on your machine and select the source as Exchange Server. Then, depending on whether you are moving to the cloud or remaining on-premise choose the destination as Microsoft or Exchange Server respectively.
Step 2. Under the Workload section select what items you want to move and apply a corresponding date filter as well.
Step 3. In the Source Screen, you need to fill in the Exchange Server details and validate them.
Step 4. Likewise, on the Target validation screen add the required details(this is different for the endpoint you select i.e. M365 cloud or on-premise Exchange) ones Validated press Next.
Step 5. The user mapping screen is where you can select any one out of three mapping options which are Fetch, Import, or Download.
Step 6. Use the preview screen to make the last level user selection and priority assignment. Validate and Start migration.
Conclusion
October 14 2025 marks the date when Exchange 2016 and 2019 end of life occurs. So organizations must make the necessary preparations and transfer their infrastructure before that. In this blog, we have explained why, what and how to do it in the most easy way possible.
