SMTP via commandline (OLD knowledge being documented so I won’t forget it again)

This is being put here because I always forget the syntax for the SMTP command syntax when testing a mail server SMTP functionality by hand.

telnet mailserver.whatever.com 25
helo
mail from:myaddress@mydomain.com
rcpt to:whoiamsendingthisto@testdomain.com
data
from:
subject:this is a test
this is the body of the message, implement me as necessary.

.

And that’s it. That sends a test message through the smtp gateway just as your coveted Outlook does.