Forum Discussion

rreimche's avatar
rreimche
Copper Contributor
Dec 08, 2021

Migrating legacy mailboxes from on-premises Exchange Server to already operation 365: problems?

Hello,

 

I need to migrate legacy mailboxes from an on-premises Exchange Server to 365. 365 is already fully operational and is being used for a while.

 

The whole setup looks like this. Inside the company network a DNS Server points to the local Exchange Server for Emailexchange. From outside, however, MX records are configured to point to 365.

I am planning to connect the on-premises server in minimal hybrid mode and migrate the mailboxes. However, I see that this is not a normal case, where hybrid configuration is being started with empty 365. This is why I wonder, if can simply apply the normal migration procedure to copy mailbox data. Mailbox names are equal on both sides.

 

After migration of the legacy data we plan to shut down the local Exchange Server.

 

Do any other possible problems come to your mind?

 

Thank you in advance,

Roman

exchange
office 365

2 Replies

  • surajbudhani's avatar
    surajbudhani
    Icon for Microsoft rankMicrosoft
    Dec 08, 2021
    Ideally the plan should work just fine with no issues.
    Can you be more specific about the type of migration you refer to when mentioning "normal migration procedure to copy mailbox data."
    • rreimche's avatar
      rreimche
      Copper Contributor
      Dec 10, 2021
      I think I'd use this guide: https://docs.microsoft.com/en-us/exchange/mailbox-migration/use-minimal-hybrid-to-quickly-migrate

      But also this one looks good: https://blog.quadrotech-it.com/blog/how-to-migrate-exchange-to-office-365-step-by-step-part-1/