In what order will the data be migrated?


In what order will email migrations be migrated by ODM?

Will you be migrating from new dated emails? Or is it from an old dated email? Or is it in no particular order?

That is, if some error occurs in the middle, I would like to know the specification of which period the data migrated halfway will be migrated first.

Best regards

  • Hello  

    Thanks for posting to the On Demand Migration (ODM) forum. I understand you would like to know the order in which email data is migrated. This really depends on what options are selected when going through the email migration wizard. In general, data is migrated in the following order:



    Distribution Lists




    In regards to the order of items migrated in terms of date, they are migrated in the order that they are provided by Microsoft. If you would better control the dates of migrated items, you can certainly implement a date filter when going through the migration wizard. Many customers have found success migrating older data first, such as 90 days old and older, then following up with a migration of newer data closer to the cutover. If you opt for this approach, I would suggest allowing for a one day overlap in your date filters to account for UTC time.


    If a migration were to stop or be intentionally stopped mid-flight, then we would suggest simply running the migration again. ODM includes duplicate detection logic by design, so any items that were successfully migrated will not be duplicated. This KB article, "What do I need to know about remigrating a mailbox with ODM?", provides additional details.


    Please let me know if you have any additional questions or need any additional clarification.




    Trevor Taegder

    Senior Technical Support Engineer

    Quest | Support