I’m working on an Exchange Server to Microsoft 365 migration where the archive mailboxes contain several years of historical emails. The migration itself is only one part of the process; I’m more concerned about verifying the data afterward.

For those who have handled this type of project, what is your process to Migrate Archive Mailbox to Microsoft 365 and confirm that everything has transferred correctly? I would normally check the number of emails, folder structure, attachments, and different date ranges. However, with hundreds of GBs of archive data, manually checking everything isn’t practical.

I’m also considering whether it makes sense to migrate the data in stages rather than transferring an entire archive at once. If a migration is interrupted, being able to continue without copying the same emails again would also be useful.

While researching possible solutions, I found SysInfo Office 365 to PST Export Tool. It appears to include options for skipping previously migrated data, removing duplicate emails, applying date filters, and generating migration reports. These features seem useful for administrators who need to monitor a large archive migration and perform post-migration verification.

I’d like to hear from anyone who has completed a similar Exchange archive migration. What checks did you perform after the transfer? Did you compare mailbox counts, attachments, folders, or migration reports? Also, were there any unexpected issues with older emails or archive folders after they became available in Microsoft 365?

Read More: https://www.sysinfotools.com/blog/migrate-archive-mailbox-to-office365/