If one wants to use seriously low bandwidth, the best way to cope is to use ssh to the shell machine, and there use pine/mutt/elm/... to read the e-mails.
If you're at all concerned about security, I'd be wary of reading email on
Bolt, the shell machine, which doesn't look like it's being actively maintained.
(Some examples: Bolt is running pre-Fedora Red Hat Linux 7 which has been
past end-of-life for a decade, the version 2.4 kernel it's running was built more than
3.5 years ago, and its sshd and openssl are even older, so it's hard to see how they
wouldn't have quite a few unpatched security vulnerabilities by now.)
If I'm misinterpreting Bolt's cruftiness and it actually is being kept up to date despite
appearances, I'd be glad to be corrected.
Otherwise, if you are reading email on Bolt, it would probably be a good idea to use a
different password than for any other sites you use.