msmtp-scripts
Wrappers around msmtp for use as queueing MTA with extra features
This project builds on top of the (and adds additional) scripts included with msmtp (a command-line send only email client) in order for it to act as a queueing Mail Transport Agent (by acting as the sendmail command; it also offer an minimalist SMTP server mode) with some additional features like verify-before-send (which requires you to confirm that you really do want to send email, after a required delay (cooling off period)) for those who need to think twice about the wisdom of what they send, or who tend to notice their grammar spelling errors after the fact.