Migration readiness check

Do you have a complete inventory of what is moving (users, mailboxes, sites, servers, apps) with sizes?

Does every item have a named business owner who will sign off that it works?

Have you mapped dependencies (apps that use the mail server, file paths in scripts, integrations)?

Have you chosen a method for each workload and written down why?

Is there an agreed sponsor, scope and go-live window?

Is there a risk register with owners and mitigations for the top risks?

Is the change approved through your change process (or the business owner) with a rollback plan attached?

Are target licences bought and a plan made for when to assign them?

Is every source account mapped to a target account (and conflicts resolved)?

Do the people doing the work have the admin roles they need in every system, tested?

Is MFA or the target sign-in method ready, with break-glass accounts set aside?

Have you cleaned up what you do not need to move (stale data, old versions, unused mailboxes)?

Are retention, holds and data-location requirements checked for the target?

Is there a verified backup of the source you can restore from?

Do you know how you will prove the data arrived (counts, sizes, spot checks)?

Do you know who hosts DNS, have access, and have TTLs lowered (or a plan to)?

Have firewall, proxy and bandwidth requirements of the migration tool been checked?

Has a pilot with real users passed, and were its lessons written into the runbook?

Have users been told what changes, when, and what they must do?

Is there a timed cutover runsheet with owners and a go / no-go decision point?

Are rollback triggers agreed and is the source kept available until the rollback window closes?

Is hypercare staffed for the first days after go-live?