Cutover Exchange Online Migration — Third-Party Hosted Exchange to Microsoft 365

It moves mailbox data from a third-party hosted and managed Exchange Server to Microsoft 365 Exchange Online using a cutover migration. It is designed for scenarios where the customer does not have direct administrative access to the source server and migration can be performed using each user's credentials.

The service is currently offered free (Microsoft sponsored). Optional additions — such as the email caching service during MX cutover, expanded documentation, or training — are scoped and priced separately.

The engagement runs as a 30-day service covering kickoff, analysis of the current Exchange solution, migration preparation, pre-stage migration, MX record cutover, final migration, and post-migration tasks. The plan may vary depending on your needs.

Mailbox content from the hosted Exchange server, including emails, calendars, contacts, tasks, and other mailbox data. The success criteria specifically include mailbox content such as emails, calendars, and tasks being migrated to Exchange Online.

Yes — this is the scenario the service is built for, provided migration is possible using each user's credentials. You supply logins and passwords for the users involved, change those passwords before migration, or provide a server admin account. Without usable authorization data, the migration cannot proceed.

A new Microsoft 365 tenant without users (or with user accounts IT Partner can delete); user logins and passwords for the mailboxes being migrated, readiness to change them before migration, or a server admin account; and access to your email domain DNS zone.

Email service may be unavailable during MX record switching, and the downtime depends on your DNS provider's settings and the DNS behavior of email senders. An additional email caching service can spool inbound mail during the MX switch so messages are received regardless of the cutover duration — it is an optional add-on, scoped separately.

IT Partner changes DNS settings, including the MX record, to direct mail flow to Exchange Online, and controls their application. Incremental mailbox synchronization catches emails sent after the main synchronization starts, so mail that arrives during the transition is carried over.

Yes. IT Partner creates Microsoft 365 user accounts, assigns Exchange Online licenses, and adds and validates your email domain or domains in Microsoft 365. This is why the tenant must be new (or its existing accounts deletable) — the destination mailboxes are built as part of the service.

IT Partner resolves migration issues and errors as part of the service, and the deliverables include a report showing the number of mailboxes successfully migrated and any that could not be, with final status and outstanding issues carried into the closeout documentation.

The success criteria include Exchange Online Protection configured and working and necessary transport rules created and working. The standard scope is a baseline sufficient for production mail flow — accepted domain validation, MX routing, and baseline anti-spam and anti-malware policy validation, plus the transport rules identified during discovery as required for basic mail flow. Advanced Defender for Office 365 features, complex mail-flow redesign, and compliance routing are separate security work.

Customer team training (available as an additional service), desktop software settings, and end-user support. Users are expected to access Exchange Online after migration, but hands-on configuration of Outlook profiles, mobile devices, or individual desktops is outside the scope and can be arranged separately.