Rather than attempting to determine an issue without anyone else, you can counsel with our specialists. Our administrations are accessible through different methods of correspondence. You can benefit our help with the telephone call, remote access, and email talk. So approach us legitimately to settle all Microsoft Office 365 issues in a matter of moments.

How to Migrate from Exchange 2019 to Office 365

For Exchange servers 2003 and later, cutover migration is recommended especially if you would like for the migration to span a couple of days as opposed to a longer time frame. A cutover migration is a process which must be completed in one go. Microsoft emphasizes that, although this method enables to migrate up to 2000 mailboxes, it is recommended not to exceed 150. This way, admins can ensure better stability and reduce the risk of many undesired errors.

Step-by-step cutover migration guide:

This checklist shows how to perform a cutover migration.

  1. Update your source system and download all service packs.
  2. Enable Outlook Anywhere, to allow for remote connection to the on-premises Exchange Server when the proper migration starts.
  3. Make sure that the administrator’s account you will use for migrating has full access to all mailboxes. 
  4. Add an SSL certificate with Outlook Anywhere and Autodiscover services included.
  5. Optional: Test if you can connect to your Exchange organization using Outlook Anywhere. You can find instructions on how to do that in Test and Verify Autodiscover on TechNet.
  6. Disable Unified Messaging before the migration and turn it on only after the migration is complete.
  7. Create Security Groups on Office 365: If you want to migrate security groups, you have to remember that email migration service can migrate them only if you create them before the migration
  8. Create Migration Endpoint – A Migration Endpoint is a container for settings and users’ credentials. The data included in it is necessary to access both the source and the target server; it stores settings defining the maximum number of mailboxes to be migrated simultaneously, and a maximum number of concurrent incremental syncs. Note that a single Endpoint can handle up to 100 concurrent mailbox migrations, including syncs.
  9. Create the migration batch, containing every single mailbox which is going to be transferred, and choose whether to start the batch instantaneously, or manually later.
  10. After the data transfer is finished and the TTL (Time-to-live) passes, the DNS MX record needs to be changed, so that mail is now routed to Office 365 mailboxes (the time for this change to apply varies; it may take up to 24-48 hours)
  11. Ensure that data in the migration batch has been synced at least once since emails began to be routed directly to Exchange Online mailboxes. When ready, delete the migration batch.
  12. Last but not least, licenses must be assigned to the migrated accounts. To prevent users’ accounts from being disabled, it has to be done within 30 days.

As for post-migration tasks, an Autodiscover record has to be created in DNS. It is necessary for users to connect easily to respective Office 365 mailboxes. More on creating DNS records in Office 365 here.

At this stage, it might be a good idea to verify if the Autodiscover service is working. If everything went well, the on-premises Exchange can be removed from your server.

For more information on the cutover migration process, consult this Microsoft Support article.

LG Networks, Inc.

ALG Networks Inc., our computer support and IT consulting help strengthen your business, delivering service and support at one flat, affordable rate. Supporting businesses in Dallas, Garland, Plano, Richardson, Addison and Irving, our computer support technicians can help you achieve the fastest return on your technology investment.