Migrate Exchange Online mailboxes to another tenant

Mail in every folder, contacts and calendars – no invitations sent, safe to run again.

O365 Migration3 steps10 minutes to set up

Before you start

  • Both tenants on the Tenants page.
  • Destination mailboxes licensed for Exchange Online.

Step 1: List the mailboxes

Open Exchange, pick the tenants, then Import CSV (SourceMailbox,DestinationMailbox), Add from source or Fill destinations. Click Check.

Exchange screen with source and destination mailboxes, check results and options

Step 2: Choose what to migrate

Mail (every folder, read state, flags, dates, attachments), Contacts and Calendars; skip Deleted Items and Junk Email; only items since a date.

Step 3: Start and check the report

Click Start migration or Schedule. Events are created without attendees, so nobody receives an invitation – the organizer and attendees are noted in each event.

Exchange migration report

Good to know

  • Every item carries its source ID: running again adds only what is new.

Need help?

Search the help center, open a support ticket, or let us run the migration for you.

Related guides

O365 Migration

Migrate OneDrive to another Microsoft 365 tenant

Every user's OneDrive with folders, files and dates – into the root or a folder of your choice.

3 steps · 10 minutes to set up
O365 Migration

Migrate Gmail to Exchange Online (Microsoft 365)

Every user's Gmail with labels as folders, contacts and calendars – from a CSV of users.

6 steps · 30 minutes (first time)