Notmuch is a very thin front end on top of xapian. Much like sup-mail, it focuses upon indexing your email messages.
Notmuch is written in C and an order of magnitude faster than sup-mail. Notmuch can be terminated during the indexing process, on the next run it will continue where it left off. Also like sup-mail, it does not provide a way to permanently delete unwanted email messages. It doesn't fetch or send mails, nor does it store your email addresses, you'll need to use programs like offlineimap, msmtp and abook for those tasks.
It provides python, vim, and emacs bindings. It is available from AUR.
First time Usage
The program prompts you for the location of your maildir
The program prompts you for your primary and secondary email addresses
Running it as an email client
vim -c NotMuch