Best Practices on reply-by-email

I have never made a post via an email, so I’m admittedly clueless. But are there any situations where someone might be able to email but not have a browser? eg. at home I have my desktop browser, but on a long commute I can only send emails. Not a matter of preference, but a matter of ability.

In other words, not that I am participating only with email, but that I participate both ways.