Completed [00000008] Exchange Online Mailbox Migration — Wave 3
·Maintenance Summary
The third wave of the Exchange Online migration moved 450 mailboxes from on-premises Exchange 2019 to Microsoft 365 between 2:00 AM and 6:00 AM on March 30.
Results
| Metric | Value |
|---|---|
| Mailboxes migrated | 450 |
| Failed migrations | 0 |
| Average migration time | 4.2 minutes per mailbox |
| Total downtime per user | < 90 seconds during cutover |
Post-Migration
- Outlook clients auto-reconfigured via Autodiscover
- OWA redirect from on-premises URL active
- Archive mailboxes migrated in parallel
