ruby-mail 2.6.4+dfsg1-1 (amd64 binary) in ubuntu bionic

 The purpose of this library is to provide a single point of access to
 handle all email functions, including sending and receiving
 emails. All network type actions are done through proxy methods to
 Net::SMTP, Net::POP3 etc.
 .
 Built from experience with TMail, it is designed to be a pure ruby
 implementation that makes generating, sending and parsing emails a no
 brainer.
 .
 Finally, Mail has been designed with a very simple object oriented
 system that really opens up the email messages you are parsing, if
 you know what you are doing, you can fiddle with every last bit of
 your email directly.