This is a bit tangential, but I'm curious about the migration path from, say Dovecot to something like this.

I have a Dovecot mail store ~(10gb of mail) on Mailcow (which is Postfix and Dovecot under the covers) and tools like mbsync fail to pull all my mail without multiple invocations. I've been looking for a migration path off it.

When I migrated to this system, I found an IMAP to IMAP script that I had to fiddle with and hack, which tool roughly a day to complete. I'm hoping for a more straightforward migration path in the future.