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JB306's avatar
JB306
Copper Contributor
Jul 30, 2019

Exchange 2010 to O365 changing from Cutover to Hybrid

I have one site that I started with a cut-over migration but now I am thinking that I need more time since I am migrating 70 users. Is there going to be some issues changing from one to the other? About 75% of the mailboxes are confirmed copied but we can't make that cut-over in one or two days. If it can be switched without issues, then great. I didn't want to do anything until I heard back from someone that has done this before. 

exchange
migration
office 365

4 Replies

  • ankit shukla's avatar
    ankit shukla
    Iron Contributor
    Jul 31, 2019

    JB306  If more than 75% is done already, there shouldn't be any issues going forward. Ensure to plan your MX and CNAME for AutoDiscover be updated on your Global DNS Registrar of the Domain. Once you press Complete, Your Mailboxes are in provisioned (Un-Licensed) state on the Office 365 end. MX Routing to (Domainname.mail.protection.outlook.com) will need to be done immediately to ensure no Missing emails to recipients on Cloud. Post which ensure to update CNAME too asap (responsible for Outlook Configuration ) without which your user won't be able to configure their Outlook. Rest other addresses that needs to be updated based on what all services (Skype/Etc) you can refer them here - https://docs.microsoft.com/en-us/exchange/mailbox-migration/cutover-migration-to-office-365 

    (Refer - the section - https://docs.microsoft.com/en-us/exchange/mailbox-migration/cutover-migration-to-office-365#optional-reduce-email-delays ) 

     

    That should be all.

     

    Cheers !!

    Ankit Shukla

     

    • R--R's avatar
      R--R
      Copper Contributor
      Jul 31, 2019

      If already 75% is completed then you should go for cutover and wait to sync 100%. If you want to go for hybrid then you have to remove the batch from O365 and then remove the accounts from O365 which are syncing. Then setup hybrid.

      • Johnny777's avatar
        Johnny777
        Copper Contributor
        Aug 01, 2019

        thanks for the advice. I am actually going to start this over using the Hybrid setup. I just converted a different site a couple of weeks ago and there were about 40 accounts to move. Cut-over was problematic as it appeared that even though it said that they were all synchronized, about 10 users found that they were missing gobs of messages. There were two of us working on this and it took two days to get it finalized. It was just lots of work which I feel could have gone smoother even though we were never in crisis mode.

         

        This next site, I'm doing myself and won't have help and for that reason, that is why I want to switch over to the Hybrid method.

         

        thanks to both for the advise.

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