A lot of offices are still running their own Exchange server for email, without realizing it. This guide covers a few signs you’re still on Exchange instead of Microsoft 365, such as a physical mail server in your office, Outlook asking for a server name when you set up a new computer, or webmail at your own domain instead of outlook.com. It also covers why Microsoft ending support for Exchange Server 2016 and 2019 on October 14, 2025 matters, and what moving to Microsoft 365 involves at a high level: an assessment, a new tenant, copying your mail over ahead of time, a cutover, and setting up Outlook and phones afterward.
A few signs you’re still on Exchange
None of these show up if you’re already on Microsoft 365, outlook dot com, or office dot com.
Why this matters right now
- Microsoft ended support for Exchange Server 2016 and 2019 — October 14, 2025: no more security updates, ever
- New vulnerabilities are never patched — And attackers actively look for servers that are no longer getting updates
- Compliance and cyber-insurance questions — Many insurers and compliance frameworks expect software that’s still supported
- Aging hardware, with no vendor support — If the server itself fails, there’s no fix from Microsoft to fall back on
Is your office still on an old Exchange server?
1An assessment of what you have now
Mailboxes, users, domains and devices, so nothing gets missed before anything is built.
2A new Microsoft 365 tenant, built and licensed
Set up and ready, completely separate from your current email.
3Your mail, calendars and contacts copied over
Done ahead of time, while everyone keeps working on the old system.
4A cutover, with zero downtime
Once everything is built and synced, the switch happens on a schedule you choose.
5Outlook and phones set up afterward
A short, guided step for everyone on the team.
Why Naples Computers
- A Microsoft Partner, hundreds of migrations — From Exchange, hosted mail, GoDaddy, Google Workspace and more
- Modern spam filtering, included in the move — We add N-able Mail Assure spam filtering as part of the migration
- Start with a migration assessment — Call 239-513-1960, and we’ll tell you exactly what moving would involve for your office
Recap: is your office still on an old Exchange server?
- Server in the closet, or a hosting company’s webmail?
- Outlook asking for a server name?
- Support ended October 14, 2025
- Growing security and compliance risk
- Microsoft 365 moves with zero downtime
- Start with a migration assessment
Printable quick guide
Frequently asked questions
How do I know if my office is still running an Exchange server?
A few signs: a physical mail server somewhere in your office, Outlook asking for a server name (not just an email address) when you set up a new computer or new hire, or webmail at your own domain or a hosting company’s own login page instead of outlook.com or office.com.
What happened to Exchange Server 2016 and 2019?
Microsoft ended support for Exchange Server 2016 and 2019 on October 14, 2025. That means no more security updates, so new vulnerabilities are never patched, and it can raise compliance or cyber-insurance questions, since many insurers expect software that’s still supported.
Do I have to move to Microsoft 365 right away?
An unsupported mail server is a growing risk rather than an emergency that has to be solved today, but the risk only grows the longer it runs. Starting with a migration assessment lets you see exactly what moving would involve for your office, on your own timeline.
Will moving to Microsoft 365 cause downtime for my office?
It doesn’t have to. Naples Computers has done hundreds of email migrations with zero downtime, by copying mail over ahead of time and holding the cutover until everything is ready. We cover exactly how that works in our next video.
What’s involved in moving from Exchange to Microsoft 365?
At a high level: an assessment of your current mailboxes, users, domains and devices; a new Microsoft 365 tenant built and licensed; your mail, calendars and contacts copied over while you keep working; a cutover; and setting up Outlook and phones afterward.
Related guides
Source: Exchange Server 2019 (Microsoft Lifecycle)