Exchange 2019 Mailbox Migration Error - Folder conflicts with Exchange Online folder

Hi there,

I’ve faced similar issues while migrating from Exchange 2019 to Office 365. Errors like AggregateMailboxFolderConflictPermanentException often happen because of system folder conflicts, and even empty or hidden folders can trigger them.

In my experience, using EdbMails Exchange Migration helped streamline the migration process:

Preserves mailbox hierarchy – All folders from the source Exchange mailbox, including subfolders and system folders, were migrated to Office 365 while keeping the same structure.

Concurrent mailbox migration – Allowed multiple mailboxes to migrate simultaneously, saving time.

Incremental migration – Any partially migrated data was synced without duplicating items on retry.

Direct Exchange 2019 → Office 365 migration – Enabled moving mailboxes, archive mailboxes, and public folders directly without needing PST exports.

With EdbMails, we were able to successfully migrate mailboxes while maintaining the same folder hierarchy in the target Office 365 mailboxes.

If you’re planning an Exchange 2019 → Office 365 migration, I’d recommend considering EdbMails Exchange Migration, especially when preserving mailbox structure is important.