Following this change you can easily watch/track or mute a topic via email without opening the web browser.
https://github.com/discourse/discourse/commit/b2187301fdf70efc42df7356b176c9c53129359c
If you wish to watch a topic, reply to a notification email with the word watch
If you wish to track a topic, reply with the word track
If you wish to mute a topic, reply with the word mute
This is an extension to Feature: Like via email
The feature has no help, that said, I am open to possibly having “too short” email teach people about this.