Outlook client profile updating utility
if the id's of the mail items aren't preserved when migrating from one server to another)?
I have about a dozen users and their workstations aren't managed by Active Directory but I'm happy to run through a few steps with each of them.
In a few cases you will end up re-creating profiles - I've not had a single migration yet where that was not the case so I always prepare for that.
If no one is using the old mail server any longer AND the original client configuration was setup by Autodiscover, it should be as simple as updating the Auto Discover A record to point to O365 (which is part of the migration process).
Also - if you have internal users and have not decommissioned your Exchange server than Outlook with pickup settings via SCP entries for Active Directory.
This is a good way to change user habits as well - as most don't need all their mail offline (and search is integrated so they can still find their mail).To resolve this, you need to create a new Outlook profile and set it as the default one.Outlook should now open without any errors and connect to the correct Exchange server.Modify your profile to ensure that you are using the correct Microsoft Exchange information service.This happens because the pre-migration settings of the Autodiscover service, which connects Outlook with Exchange, are still cached in the registry for the currently used Outlook profile.