How to migrate 200GB+ mailbox from Gsuite to O365 E3 plan?

Copper Contributor

I have Gsuite users whose data are more than 200GB & i am migrating that users to O365 E3 plan where we get 100GB primary mailbox & unlimited Inplace archive storage where i can apply retention policy only after migrating users whole mailbox from gsuite to o365. But how to migrate 200gb+ data to 100gb storage at the time of migration?
Kindly suggest.

5 Replies
This is not possible - clean up the mailbox under 90GB. Or you split the mailbox in different parts and create a archive in M365.
Hi Vijay, were you able to migrate that big mailbox, ?



Hi, I'm about to do a similar task.  THough I'm looking at how to do this each step.


I am moving users from an exchange service that is shutting down and move their massive mailboxes to something else, perhaps to an O365 E3 plan.  are there any other choices ?


Would suggest to minimize the size of mailbox before migration, say extract to PST, after that, you may consider to drag and drop from PST to Online through Outlook

Hi @Mayur_Vijay_More, there are tools out there that can migrate these mailboxes. For example Bittitan. However, it is important to enable auto expanding of the archives, so the total amount of data can be migrated. You also need to keep in mind that the automatic expansion is an automatic process that will only start when the archive is at 90% of its capacity. Therefore, the migration will take some time with a lot of retries, because of that process.