Why should You Move Off Exchange 2016 Now?
Microsoft states that support for Exchange Server 2019 and 2016 ended on October 14, 2025. Existing servers continue to work, but Microsoft gives no more fixes or support.
Microsoft names two options. Migrate mailboxes to Microsoft 365, or upgrade to Exchange Server Subscription Edition. Microsoft recommends that you migrate mailboxes to Microsoft 365 and use Exchange 2016 or 2019 to connect and move them.
Which Migration Path Fits Your Organization?
| Path | Fits | Key limit |
|---|---|---|
| Cutover | Small organizations | Fewer than 2,000 mailboxes, 150 or fewer advised |
| Hybrid | Larger organizations or gradual moves | Needs the Hybrid Configuration wizard and directory sync |
| Migration software | Batches, filters and retries | Check the version list of the vendor |
Microsoft lists these types for Exchange Online. Our cutover vs staged vs hybrid guide compares them in detail.
How do Cutover and Hybrid Moves Work?
Method #1: Cutover Migration (Free)
Who it suits. Organizations under 2,000 mailboxes. Extra application. None.
Microsoft requires Outlook Anywhere, a trusted certificate, a verified domain and MRSProxy. Create the migration endpoint and batch, point MX to Microsoft 365 after the sync, then assign licenses and create the Autodiscover record.
Method #2: Hybrid Migration (Free)
Who it suits. Larger organizations that need both sides to work together. Extra application. Hybrid Configuration wizard.
Microsoft describes a hybrid deployment as a link between Exchange on premises and Exchange Online for coexistence or migration. Start the wizard, sync your directory and move mailboxes in batches with a remote move.
What if You Want Batches Without a Hybrid Setup?
Method #3: Migration Software (Paid After Demo)
Who it suits. Admins who want filters, retries and delta sync. Extra application. Exchange to Office 365 Migrator.
The Exchange to Office 365 Migrator lists Exchange 2010, 2013, 2016 and 2019 as sources. It moves emails, contacts and calendars, processes batches of up to 200 mailboxes, filters by date and category and handles delta migration.
Failed items can retry. Test the demo with a few mailboxes.
What should You do Before and After?
- Follow the Exchange Online migration checklist for licenses, DNS and the pilot.
- Check mailbox sizes against the Exchange mailbox size limits.
- Plan shared mailboxes and public folders on their own. See the guides on how to migrate a shared mailbox and how to migrate public folders.
- Decommission the old server only after Microsoft Support advice.
Frequently Asked Questions
When did Exchange 2016 Support End?
Microsoft states that support for Exchange Server 2016 and 2019 ended on October 14, 2025.
Does Exchange 2016 Stop Working After That Date?
No. Microsoft states that installations continue to work, but it gives no more fixes or support.
What does Microsoft Recommend?
Microsoft recommends that you migrate mailboxes to Microsoft 365 and upgrade your environment to Exchange Server SE.
Which Method Suits a Small Organization?
Cutover migration suits fewer than 2,000 mailboxes. Microsoft advises 150 or fewer.
When do You Need Hybrid?
Use hybrid when both sides must work together or when you move in batches over time.
Does Migration Software Support Exchange 2016?
The vendor page lists Exchange 2010, 2013, 2016 and 2019 as sources.
How Many Mailboxes can the Software Move at Once?
The vendor page lists batches of up to 200 mailboxes.
Author's Verdict
Choose cutover for a small team and hybrid for a large or gradual move.
Use software when you want filters and retries, and test the demo on a few mailboxes first.
Key Takeaways
- Support for the server has ended.
- Cutover fits smaller organizations.
- Plan shared mailboxes and public folders on their own.
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