Moving a business to Microsoft 365 doesn’t have to mean email going down for a day. This guide walks through Naples Computers’ seven-step process, used for hundreds of migrations of every kind (Exchange, hosted mail, GoDaddy, Google Workspace and more), for moving to Microsoft 365 with zero downtime: an assessment, a new tenant built and licensed, mail copied over while staff keep working, holding the MX record until everything is ready, the cutover itself, a final sync, and setting up Outlook and phones afterward.
Why zero downtime is possible
The trick isn’t speed. It’s controlling exactly when your office switches over, down to the minute.
What a Microsoft 365 migration looks like, step by step
1We assess 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
Your new environment is set up and ready, completely separate from your current email.
3Mailboxes, calendars and contacts, copied over
Everything gets copied into the new tenant while your office keeps working on the old system.
4The MX record is held, not changed, yet
The MX record is what tells the internet where your email actually goes. We leave it exactly where it is.
5The cutover: the MX record is switched
Once everything is built, synced and double-checked, we switch the MX record, usually scheduled outside business hours.
6A final sync catches the last messages
Any mail that arrived during the switch gets picked up, so nothing gets lost in between.
7Outlook, phones, and a short training
A short, guided step for everyone on the team: sign in on their computer, their phone, and a quick walkthrough of what’s new.
Recap: a Microsoft 365 migration with zero downtime
- Assess what you have now
- Build and license the new tenant
- Copy mail over while you keep working
- Hold the MX record until everything’s ready
- Cutover: switch the MX record
- Final sync catches the last messages
- Outlook, phones, and training
Printable quick guide
Frequently asked questions
How is a Microsoft 365 migration done with zero downtime?
Mail, calendars and contacts are copied into a new Microsoft 365 tenant while staff keep using the old system. The domain’s MX record, which tells the internet where email actually goes, is held in place until everything is built and synced, then switched on a schedule you choose. A final sync afterward catches any messages that arrived during the switch.
What is an MX record, and why does it matter for a migration?
An MX record is the DNS setting that tells the internet which mail server handles a domain’s email. Updating it is what actually points your domain’s mail at Microsoft 365, so leaving it in place until everything is ready, then updating it, is what controls exactly when the cutover happens.
How long does a Microsoft 365 migration take?
It depends on how much mail there is to copy and how many mailboxes are involved, but there’s no deadline during that part: staff keep working on the old system the whole time. Only the cutover itself, switching the MX record, happens at a specific, scheduled moment.
What happens to email sent during the cutover?
A final sync after the cutover catches any mail that arrived during the switch, so nothing gets lost in between the old system and the new one.
What kinds of email systems can be migrated to Microsoft 365?
Naples Computers has done hundreds of migrations from Exchange Server, hosted mail, GoDaddy, Google Workspace, and standard IMAP or POP email, all using the same zero-downtime process.
Related guides
Source: Connect your domain by adding DNS records (Microsoft 365 admin, Microsoft Learn)