I'm getting ready to migrate about 80 users from Thunderbird to Exchange Online. Currently, we're using POP3 in Thunderbird, with all mail stored as mbox files on two local NAS devices, totaling around 70 GB of data. There's no IMAP or server-side source available, so I'm seeking advice on how to make this transition smooth before fully committing to it. Any tips or experiences would be greatly appreciated!
3 Answers
Your best option is to convert those mbox files to PST format for import into Outlook. It's a tedious process, and you may feel ready to quit at times, but it'll be worth it in the end. Just a heads up, get ready for your users to have a ton of questions about Outlook once the migration is done. Good luck with it!
I've migrated POP mailboxes before, and here's what worked for me: First, switch the users to Outlook so that no mail is sent to the old POP accounts. Then, export the mbox files as PSTs and import them into Outlook. Doing this after hours can help minimize disruption for users. Just make sure emails are routed to Outlook right away to avoid missing any new messages during the switch.
What about the 2 GB limit on exports from Thunderbird?
Definitely the right approach! Consider using StellarInfo software for the process.
Since you don't have IMAP, migrating to Exchange Online will be tricky. You could add the Exchange Online account as an IMAP account to Thunderbird for each user, then manually drag and drop the emails. After the migration, just remember to disable IMAP again in Exchange. This method isn't ideal, but it's a workaround. Good luck! 💪
Yeah, that won't work for us; the provider lacks sufficient space.
Totally agree! Converting to PST sounds like the best route.