Check which ports are open to the outside world. Helps make sure that your firewall rules are working as intended.
One of a set of tools we are providing to everyone as a way of saying thank you for being a part of the community.
#! /bin/sh nc mymailserver.com 25 << FIN EHLO mymailserver.com auth plain aaaa_MYBASE64PASSWORD___aaa MAIL FROM: email@example.com RCPT TO: $1 DATA Subject: $2 $3 . quit FIN