Migrating from Exchange to Microsoft 365? Do not let your company split in two.
Mailbox migrations rarely happen overnight. For weeks, half the company sits on Exchange Server and half in Microsoft 365, and nobody can see anybody's calendar. That is where meetings get missed and the migration project gets the blame. AddSync keeps both sides in step until the last mailbox has moved.
What goes wrong in the middle of a migration
Every company that moved in waves has told us a version of this.
Invisible calendars
People on the new side cannot see free and busy of people on the old side. They book blind.
Duplicated meetings
Users copy events by hand to stay safe. Copies drift, and nobody knows which is right.
Delayed waves
Every complaint pushes the next wave back. A short pilot becomes a long project.
What AddSync does, and what it does not
We are clear about it, because migrations punish vague promises.
AddSync keeps calendars, contacts and tasks in step between Exchange Server and Microsoft 365, in the direction you choose, while people move over in waves.
AddSync does not move mailboxes. Use Microsoft's tools or your migration partner for that. We cover the gap they leave: the weeks when two systems must behave like one.
A migration plan that survives contact with the users
Inventory
List who moves in which wave and who shares calendars across waves.
Pilot group
Sync a small group first. Check events, changes and cancellations.
Run the waves
Keep the sync on while people move. The calendars stay trustworthy.
Switch off
When the last mailbox has moved, end the sync and keep working in Microsoft 365.
And the AI question
Your people want AI on mail now, not after the migration.
With AddSync AI
- Works on Exchange Server today.
- Works on Microsoft 365 after the move.
- The same filter, approval and journal on both sides.
Without it
- Microsoft Copilot does not reach on-premises mailboxes, so the waiting staff get nothing.
- Staff pick their own tools in the meantime.
- You redo the AI decision after the migration.
Questions
Does AddSync migrate mailboxes?
No. It keeps calendars, contacts and tasks in step. Use Microsoft's migration tools or a partner for the mailbox move.
Can I choose which way data flows?
Yes. You choose the direction of the sync.
What happens when the migration is over?
You end the sync. Microsoft 365 stays as your system. If you want AI on mail, AddSync AI works on Microsoft 365 too.
Is it per account?
Yes. See pricing.
Do not let calendars decide your timeline.
Tell us how many people move and in how many waves. We will tell you what the sync takes.
