I went through a similar situation with openmailbox dot org, though of course in their case the entire service suddenly shut down. Terrible position to be in. I eventually recovered most, but not all, accounts using that email address. Huge PITA.

Ah my bad dude. Hope you figure it out.

When you get your boot fixed, there’s a nice way to automount volumes with systemd as an alternative to modifying fstab. I think this is how I did it on Bazzite:

https://www.golinuxcloud.com/mount-partition-using-systemd/