t's too bad that ProtonMail doesn't have a GUI Backup & Recovery
Tool, instead of having to recover and install backup messages
using the Terminal and DOS or Bridge which makes it more difficult and tedious.

I had no problem saving messages backup as .eml files to ProtonDrive as
a backup; restoring and importing backup messages back into ProtonMail
should be just as easy.

ProtonMail should have a more intuitive way to restore and import backup
messages back into ProtonMail.