Available email clients, front ends and tools

Shipping with Notmuch

aerc, a pretty good terminal email client written in Go that supports notmuch.
alot, a curses frontend written in Python with the Urwid toolkit.
astroid, a graphical threads-with-tags mail user agent for notmuch. Written in C++ using GTK+, WebKit and gmime.
bower, a curses frontend written in Mercury.
dodo, a graphical, hackable notmuch frontend based on Python/PyQt.
meli, curses-like mail client written in Rust.
neomutt, a fork of mutt able to use Notmuch for virtual folders.
netviel, a single-page web app with Javascript frontend and Python backend.
noservice. Web interface, written in Clojure.
notmuchfs, a virtual maildir file system for Notmuch queries.
epistula, a terminal MUA based on gpgme and gmime written in go and with tcell (alpha status).
notmuch-email-client, an extension for using notmuch in web browsers

ner, a curses frontend written in C++ (github mirror).
mutt-kz, a fork of mutt with Notmuch as a backend (actually linked against lib notmuch). Deprecated in favour of neomutt.
jaro-mail. Command line client emphasizing privacy. (github mirror)
notmuch-web A web front end written in Haskell. Not active upstream since 2014.

patches, a patch tracking system.
notmuch-extract-patch, a tool to extract patches from a thread.
notmuch-import-patch can import a git branch into your notmuch database as if it had been sent to you with git-send-email(1), so that you can provide comments on the branch by e-mail to its author

notmuch-extract-patch and notmuch-import patch are included in the mailscripts package in Debian and its derivatives.