Hey folks,

Just wanted to share my recent experience with migrating mailboxes from Office 365 back to Exchange Server (yeah, a bit of a reverse move. I know it’s not common, but some specific business needs required it).

To be honest, I was a little nervous going into this because you don’t see a ton of people doing it in this direction. Most tools and documentation are geared toward going to Office 365, not the other way around.

After doing a lot of research and testing, I ended up using EdbMails Office 365 migration tool and it worked out way better than expected. The software is pretty straightforward. You sign in using your Office 365 account (modern authentication supported), select the mailboxes, and connect to your destination Exchange using EWS. No agents, no crazy setup, and most importantly, no data loss.

What I personally liked:

• The UI is clean and not bloated.
  
• It auto-maps mailboxes which saves a ton of manual effort.
  
• I could migrate selected folders using filters (like only Inbox or a date range).
  
• It handled throttling and reconnections automatically.

I didn’t have to install anything on the target Exchange either, which made things a lot smoother with our existing setup. Just installed it on one of our machines that had access to both servers and it did the job.

If anyone here is looking for a reliable way to move mailboxes from Office 365 to on-prem Exchange, I'd recommend giving EdbMails a try. They also offer a free trial so you can test the waters before committing. Helped me a lot, so just putting it out there in case someone’s in the same boat.

Cheers!