Challenge
Legacy shared calendars and delegate access broke during a previous partial migration attempt.
Approach
- Rebuilt migration plan with pilot partners and IT coordinator.
- Used staged batches with rollback DNS TTL planning.
- Validated delegate and shared mailbox permissions before firm-wide cutover.
- Staff help desk on-site during go-live morning.
Outcomes
- Cutover completed within agreed weekend window.
- Shared calendars and room mailboxes functional day one.
- Post-migration tickets closed within hypercare period.
