cat << EOF | sendmail -t
Sender: no-reply@chorke.org
From: Sender <from@chorke.org>
Reply-To: Sender <from@chorke.org>
To: To <to@chorke.org>
CC: Cc <cc@chorke.org>
Disposition-Notification-To: to@chorke.org
Subject: Generic Subject
Generic Body
EOF
Knowledge
/usr/sbin/sendmail -t < filename.eml
/usr/sbin/sendmail -v -t < filename.eml
/usr/sbin/sendmail -Am -v -t < filename.eml
env command is to launch interpreters
1. Python 3.9: #!/usr/bin/env python3.9
2. Python 2.6: #!/usr/bin/env python2.6
3. Python : #!/usr/bin/env python
4. Perl : #!/usr/bin/env perl
References