You feel that it's a liability compared to storing the 12 years of email elsewhere, or compared to just not storing 12 years of email? What about the utility of the archive compared to the liability?
Why not just download your old mail and archive it then? Google provides an easy way to do this (Google Takeout).
As in, I don't see the problem with having more storage - you use only as much as you want.
Personally, I find having all my mail searchable from any computer useful. And Google does provide lots of security features (2FA, suspicious login detection, new login alerts, login audit logs etc)
I typically export mail regularly. In my case, I store them in a DEVONthink Pro Office database as that supports directly importing from Apple's Mail.app, has good search, and good cross-referencing support.
I really wish I followed this practice sooner as there's mail from the 90s I wish I still had. I've used e-mail continuously since 1991 so it would be a lot of mail. Disk space is the main reason why I didn't do it sooner.
