aerc
aerc is a terminal-based e-mail client with Vim-style keybindings and an ex-command system. It uses an embedded teminal which allows to use any terminal-editor as an embedded component to compose e-mails. aerc comes with inbuilt support for IMAP and SMTP, but also supports Maildir and Notmuch. While aerc provides a simple wizard to set up an e-mail account, the complete configuration is handled in text files within $XDG_CONFIG_HOME/aerc.
aerc is written in Go and uses the Tcell package for the terminal UI.
Installation
Tips and tricks
Khard as addressbook provider
khard can be configured as an address book provider[1]:
$XDG_CONFIG_HOME/aerc/aerc.conf
[compose] address-book-cmd=khard email --parsable --remove-first-line %s