So the periodic archive download might be a reasonable suggestion. This is exactly what I do for the handful of domains I pointed to fastmail. I use Thunderbi

So the periodic archive download might be a reasonable suggestion. This is exactly what I do for the handful of domains I pointed to fastmail. I use Thunderbird to keep everything local and use 7zip to make snapshots of the local files and copy them to other local servers and USB drives. If AU started imposing some weird laws on Fastmail I could quickly migrate elsewhere.