I've ported email 2.3.4 to Windows (Cygwin)
Command line sending of email, optionally with GnuPG encryption.
Email is a simple command-line program to send emails. It can be configured
to use either your sendmail installation or directly via SMTP.
It supports binary attachments, and a simple text based address book, with groups.
Also, if GnuPG is installed, it can digitally sign and encrypt outgoing emails.