Should We Migrate to Microsoft 365?

For most small businesses the answer is yes, and it has been for a while. Microsoft stopped supporting Exchange Server 2016 and 2019 in October 2025, Google Workspace users increasingly want the Office applications their customers use, and a file server in a closet is the most expensive way left to share documents. The interesting questions are not whether to move but what moves, in what order, and how to do it without losing a day of email. This is a practical guide to Microsoft 365 migration for a business of five to a few hundred people.

When migration makes sense

• You run your own Exchange server. It is out of support, it needs a specialist to maintain, and a single failure takes the company’s email down. This is the clearest case.
• Your file server exists only to share files. SharePoint and OneDrive do that from anywhere, with versioning, sharing controls and no hardware to replace every five years. Our plan for getting rid of the server covers everything else it does.
• You are on Google Workspace but live in Excel and Outlook. Both platforms are good; the move is about which one your people and your customers actually use.
• A customer, insurer or auditor is asking about security. Microsoft 365 Business Premium bundles the controls they ask for: multi-factor authentication, conditional access, device management and threat protection.

When to wait

If a line-of-business application runs on the server, the server stays until that application has a cloud path; email and files can still move ahead of it. If your internet connection is unreliable, fix that first, because everything will depend on it. And if your team is mid-way through a busy season, plan the cutover for the quiet weeks; a migration is easy, a migration during tax season is not.

What moves

1. Identity. User accounts move into Microsoft Entra ID, the sign-in service behind Microsoft 365, either replacing an old on-premises Active Directory or syncing with it during a transition. Multi-factor authentication goes on at this step, not after.
2. Email, calendars and contacts. Mailboxes are copied to Exchange Online in the background, then the domain’s mail routing is switched at a quiet hour. Shared mailboxes, distribution lists and public folders need their own plan.
3. Files. Shared drives become SharePoint sites, personal folders become OneDrive, and the permissions are rebuilt deliberately rather than copied wholesale, because twenty years of file-server permissions are rarely worth preserving.
4. Applications. Office is installed from Microsoft 365 on each computer; the old Office is removed. Teams replaces whatever was doing chat and meetings.
5. Security baseline. Conditional access, device enrolment, sensitivity labels and the anti-phishing settings that Microsoft leaves off by default.
6. Backups. A separate backup of Microsoft 365, because Microsoft does not keep a copy for you. See cloud backups.

Choosing plans

Most companies end up with a mix: Business Standard or Premium for the people who live in Word and Excel, Basic or a plain Exchange mailbox for people who only need email. Premium is the right choice for anyone who needs device management, conditional access or insurer-grade security. The Microsoft 365 plan picker shows the mix in five questions, and licences are billed at Microsoft’s rate with no markup.

How a migration runs

1. Assessment. Mailbox sizes, file volumes, the applications on the server, the printers and scanners that send email, and the odd items every office has: a shared calendar from 2011, a mailbox nobody owns.
2. Tenant setup. Domain verified, accounts created, security baseline applied, plans assigned.
3. Pre-migration copy. Mail and files copied in the background over days, while everyone keeps working on the old system.
4. Cutover. At a quiet hour, mail routing switches, the final delta is copied, and Outlook is repointed. People arrive to the same mailbox in the same Outlook.
5. Files and clean-up. Shares moved, shortcuts and mapped drives updated, the old server kept read-only for a verification period, then retired.
6. Training and support. A short introduction to Teams, OneDrive and SharePoint, and a help desk that knows what changed.

The mistakes we see

Copying old permissions instead of designing new ones. Skipping multi-factor authentication because the migration was “just email”. Forgetting the copier, the alarm panel and the accounting system that all send email through the old server. Leaving the old server running “just in case” for a year. And not backing up the new tenant, then discovering that a deleted mailbox is gone after thirty days. Every one of these is avoidable in the assessment.

What it costs, and what it saves

Licences are billed monthly at Microsoft’s rate. The migration is a project, quoted after the assessment, and it is usually paid back within the first year by the server it retires: no hardware refresh, no server backup licence, no specialist to keep Exchange alive. Our cloud migration services page covers the project and our Microsoft 365 support page covers what happens afterwards.

Common questions

How long does a Microsoft 365 migration take?

For a typical office of twenty to fifty people, two to four weeks from kickoff to cutover, most of it preparation. The email cutover itself happens over a weekend or an evening, and people arrive on Monday with their mail in the same Outlook.

Will we lose email during the move?

No. Mail is copied to Microsoft 365 in the background while the old system keeps running, then the address is switched over at a quiet hour. A properly planned migration has no gap; the risk is in a rushed one.

What happens to our old server?

If it only ran email and files, it usually retires after a verification period, which removes its maintenance, backup and replacement costs. If it runs an accounting or line-of-business application, that stays until the application has a cloud path of its own.

Does Microsoft back up our data after the move?

Microsoft keeps the service running and keeps deleted items for a short time. It does not keep a copy for you. Microsoft 365 backups are a separate layer, and we recommend them for every client.

What does the migration cost?

Licences are billed at Microsoft’s rate with no markup. The migration itself is a project, quoted after a short assessment, and it is usually paid back within the first year by the server it retires.

Talk to us

If your Exchange server is out of support or your file server is due for replacement, we will assess the move and quote it in plain numbers. Call 952-548-5558 or contact us; the first conversation is free and there is no long-term contract.