I use it daily. It's a lovely email client. Close to the Unix ideal of doing one thing, and doing it well. Integration with other utilities (notmuch, isync) for indexing and sync'ing is very easy, thanks to close adherence to Unix principles, and gets you a very neat setup. Nothing to envy from Gmail.
> Close to the Unix ideal of doing one thing, and doing it well. In my opinion this concept does not work for most non-cli programs. How do you actually define this "one thing"? Is "reading an email" one thing? And "writing an email" another thing? What about "spellchecking the email"? What about "managing all my email contacts"? What about "back up my emails"? What about "sign email with GPG"? Do all of these things…
Mostly everything else is outsourced. Composing is done by your $EDITOR, sending is done by an external program, fetching email by an external program too. Even indexing and querying is usually outsourced to a modern xapian-based tool, like mu or notmuch.
This leads to powerful composable workflows.