Migrate Exchange 2016 to Exchange SE Step-by-Step Guide
When you need to migrate a mailbox from Exchange 2016 to Exchange SE, there are no shortcuts. Moreover, the various paths and no direct in-place upgrade create much confusion even among veteran admins.
I have been part of many 2016 to SE transitions recently, and I know exactly what needs to be done to ensure an error-free transfer. I will guide you through the entire process step by step and explain to you all stages from the pre-migration checklist to post-migration assessments.
Understand this very clearly with the announcement of Exchange Server Subscription Edition, Microsoft has put an end to the “reinstall every few years” cycle. Additionally, now both Exchange 2016 and 2019 are in post EOL stage, so migration becomes even more important. Let us start with the pre-migration tasks.
Pre-Migration Checklist for Exchange 2016 to Exchange SE Transfer
| Task | Status | Why It Matters (The Real Talk) |
| Full Backup | [ ] | Rollback is not supported after the schema upgrade. This is your only safety net. |
| Certificates | [ ] | Ensure your Autodiscover Proxy Certificates are ready for the new SE server. |
| Assessment | [ ] | Audit the number of mailboxes and database sizes to identify 100GB “monsters” that will stall moves. |
| Inventory | [ ] | Identify Public Folder usage; they can be a nightmare to move if not identified early. |
| Infrastructure | [ ] | Verify the presence of Exchange Server Version 2019 CU15 if you are using the bridge method |
| OS Support | [ ] | Confirm target OS is Windows Server 2022 or 2025. |
| Send Connectors | [ ] | Reconfigure these or mail won’t leave the building. |
| Maintenance Mode | [ ] | Put 2016 in maintenance mode during the final cutover. |
| Health Check | [ ] | Verify the Active Directory Schema version. |
Once all the tasks are complete, see the different paths you have for migration and choose the most suitable option.
Create Exchange 2016 to Exchange SE Coexistence Path
Unfortunately, if you try to Push Mailboxes from Exchange 2016 to Exchange SE directly, you won’t be able to do it. Microsoft has not implemented any direct bridge between the two versions. So, we have to use a multi-stage transfer.
Start by installing the new SE variant first. Make sure that your hardware is up to date.
- Download the Exchange SE ISO (needs approx 6GB of space).
- Mount the ISO and run the Setup.exe file on your server.
- Choose the default installation steps as they appear on your screen.
Now you have to move the mailboxes. You can use the GUI, but I find it too clumsy and slow, so I prefer to use the PowerShell cmdlet:
New-MoveRequest -Identity "user@domain.com" -TargetDatabase "New_SE_DB"
However, even with the efficiency of PowerShell, there were times when migration just stopped midway without explanation. Sometimes it would complete upto 95% and then get stuck. Requiring a complete reset. You don’t have to deal with all these problems just use the right tool.
Best Software to Migrate Mailbox from Exchange 2016 to Exchange SE
SysTools Exchange Server Migration Tool allows admins to transfer data with ease. Intuitive zero script UI, with precise filtering options, allows you to select and manage all the data effortlessly.
You are the one in control of the migration and can easily adjust the pace via the concurrent user settings. View all that’s happening in real-time with a dedicated dashboard area. Download the free copy today to witness firsthand how simple it is to use the tool and get the migration done in no time.
Step 1. Launch the copy of the tool and select both source and destination as Exchange Server. Choose email from the workload section for mailboxes and apply the date filter.
Step 2. Then, move to the Source Page and select the Exchange Server 2016 from the dropdown. Fill in all the details and validate. Press Next to continue.
Step 3. As you did on the source page, repeat the same steps for the destination screen.
Step 4. For mailbox migration from Exchange 2016 to SE, map the source users with the destination. For that, you can fetch all, or use the download template + import users combo.
Step 5. Once the user list is visible in the Tool dashboard, select the users whose mailboxes you need to migrate, then apply the priority marker. Validate the results and press Start.
Post Migration Validation and Cleanup
No matter what path you opt for migrating Exchange Server 2016 to the SE, this stage is mandatory if you dont want ghost issues to bother the users in the new server system.
Here is a list of checks you must make:
Outlook Connectivity: Perhaps the most crucial check from an end-user perspective. As an admin, you must ensure that the Outlook Client (New or Classic) uses the MAPI/HTTP protocol and does not fall back to the legacy ones.
OWA and ECP Access: It is not just the client that should work properly, but the web portal too. You can do this by logging in to the new Exchange Admin Center and OWA to verify the build number.
Mail Flow testing: Before you let users in, set a pilot group and let them send test emails to both internal and external recipients.
Please note that although I have tried to cover every possible best practice, it is possible that some minor activity is missing. For that, you must do a careful self-audit of your Exchange Server environment and perform the checks on your own.
Conclusion
Here, I taught you exactly what to do when you have to migrate a mailbox from Exchange 2016 to Exchange SE. The process can be done manually, no doubt about that. However, the real pain is how long it takes to complete everything. If speed is your top priority, then it is best to opt for the tool I recommend in this text. It is custom-fitted to handle all emergencies and perform the data transfer with speed and safety.