If Thunderbird moves away from file based I will find a new email client. I already have to deal with the monstrosity that is systemd, don't want my email subjugated to a database. Databases are fine for data. I want my email in files so I can easily move away if needed, to another client.
Yeah, we're sticking with thunderbird in large part for their MBOX support and if they ever dropped it we'd move to something else. MBOX makes it dead simple to parse or grep through your messages.
