Office 365 migration

Contributor II

We are in the process of migration over to Office 365 from on prem servers. Auto discover does not work for us in our environment due to having multiple domains in the name space.

We are now switching over also to using enterprise connect and unbinding from the domian.

What we are seeing in the migration is we can migrate the mailbox with no issues but on the mac client we have no easy way to change the settings on the mailbox.

What we are finding is we have to create a new mailbox with the office 365 settings and when that is setup delete the other mailbox.

Has anyone found a seamless way to migrate the mailbox or is this just what we have to do. We would really like to be able just to change the server settings but can't seem to find a way to make it work.

Has any one been able to do a seamless migration from on prem to office 365?


New Contributor III
New Contributor III


I recently done a migration which was hosted exchange and I contacted the supplier and they did not support cutover migration. I was told to manually add accounts to a Mac office app from the hosted exchange > pull OLM file and upload to new O365 mailbox I've created, I assume this is the same you are thinking of doing. Its a bit of a pain and there is more to do then you think and its not efficient.

I would suggest looking into a cutover migration and follow the instructions, theres plenty of stuff on O365. However I did not have access to on prem exchange so you have an advantage here.

In this instance all you have to do is create a migration account (global admin) I called mine o365admin and use this account when using the cutover migration tool and it will verify your old email system and pull in all the data from users emails. You will have to fill in a few others bits of info but it walks you through it.

Then users can download remove their account and re-add by simply inserting email address and password. You will also previously in the steps add your auto discover (from O365) to your DNS

Give me a shout if you need any more help but hopefully this makes sense.

Valued Contributor


Hi Mike, 

What did you end up doing? We're in a similar boat (on-prem to O365). The redirects after a migration don't take on the Outlook Mac Client. We'd have to delete the profile/account, then re-add it.