S-nail

S-nail is an easy workaround for Linux workstation which can be quickly establish, it works with gmail, yahoo and others. The following is an example tested Ubuntu 20 or Debian 10/Buster

Installatifthon

apt-get install s-nail

Configuration

This configuration is a quick sample to use TLS with STARTTLS and PLAIN which suits for almost all mail server. It already contains the USERNAME and PWD.
This way the client does not need to authenticate anymore. This example trusts the MTA and does not verify the TLS certificate, this is a workaround for missing root certificate seen often in private environments.

• Add the following to /etc/s-nail.rc

set v15-compat 
ssl-method=auto
set smtp=<your-mailserver.com>
set user=<username>
set password=<password>
set smtp-use-starttls
set ssl-verify=ignore
set smtp-auth=plain