14Oct 2025
Exchange Server 2016 and 2019 have left support
Microsoft ended support for Exchange Server 2016 and 2019 on 14 October 2025. Firms still on them have a migration to plan.
Source: Microsoft Lifecycle Policy
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Migrations with nothing left behind.
A migration is judged on the morning after: can everyone log in, is every file there and do the numbers match? Planning, test runs and validation decide the answer long before cutover night.
What it covers
Migrations and implementations
Microsoft 365 and email
Mailboxes, files, Teams and SharePoint moved from another tenant, Google Workspace or on premises Exchange.
Business application implementation
ERP, billing, CRM and practice management systems configured, integrated and tested.
Data migration and validation
Data mapped, cleaned, trial migrated and reconciled, so totals and records match before go live.
Cutover planning
A step by step cutover plan with timings, owners, checkpoints and a rollback decision point.
Testing and acceptance
User acceptance testing coordinated and defects tracked to closure. Nothing goes live without sign off.
Training and handover
End user training, documentation and support handover from day one.
- Microsoft 365
- Exchange Online
- SharePoint
- PRINCE2
How we do it
Plan
Scope, data mapping and cutover approach agreed.
Trial
Test migrations run and results reconciled.
Cut over
The live move, run to a timed plan.
Support
Early life support while users settle in.
Field notes
Worth knowing
What you receive
- Migration plan and data mapping
- Trial migration and reconciliation reports
- Cutover runbook with rollback criteria
- User acceptance test records
- Training materials and handover notes
Questions
Will staff lose email during a Microsoft 365 migration?
They should not. Mail is moved in stages and the final switch is timed to minimise disruption, usually out of hours.
Can you migrate from Google Workspace to Microsoft 365?
Yes, including mail, calendars, contacts and files.
What happens if something goes wrong at cutover?
The cutover plan sets a decision point and a tested rollback, so you can return to the old system safely if the checks fail.
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Talk to us about migrations and implementations
Tell us what you're working on. We'll listen, ask the right questions and recommend a practical next step. No obligation.
info@gabcoenterprises.com+1 345 769 4222