You are right... but are external drives with less than 1TB of space still
produced? There are flash memories but the unit cost (i.e., the cost of one
GB) is higher and they are not as reliable.
Well, it depends on where you live. In Brazil, it actually is hard (though
possible) to find a 3TB external drive for the equivalent of US$ 200.
E-mails do not take much space. Here is the space occupied by more than
62,000 e-mails I sent and received along the last 8.5 years:
$ du -sh ~/.local/share/evolution/mail/
6,1G/home/banana/.local/share/evolution/mail/
It is nothing when compared to the size of a modern disk. And those
Enigmail & gnupg2 are in the trisquel repo via your synaptic package manager
:) thats all you need for Enignmail then the wizzards does it for you ;-)
https://enigmail.wiki/
@Takumi13 you may be interested in reading : Google Has Most of My Email
Because It Has All of Yours
https://mako.cc/copyrighteous/google-has-most-of-my-email-because-it-has-all-of-yours
Although it does not really answer your question,
https://www.fsf.org/resources/webmail-systems lists "Free Software Webmail
Systems" that usually make privacy promises too.