One concern I have with moving an old Outlook archive into Microsoft 365 is organization. Some of our PST files have years of nested folders, and manually rebuilding that structure after migration would be painful.

Microsoft’s PST import documentation describes mapping PST files to mailboxes and archive mailboxes, but I’m particularly interested in keeping the original organization intact.

I’ve been looking at DRS Softech PST to Office 365 Migration Tool  because it claims to preserve the original folder structure along with email formatting, metadata, and attachments. It also has a custom folder-name option, which could be useful when we want migrated archives to follow our current naming convention rather than whatever was used years ago.

There’s also an incremental migration option. From what I understand, it can skip previously migrated items and transfer only newer or modified data, which sounds useful if the migration needs to happen in multiple passes.

For admins who have done this before, how important was folder preservation in your migration, and did you have to reorganize anything afterward?