I have an EC2 running Ubuntu with Kafka installed, I've installed mailutils on the server because I have a script monitoring diskspace on the box and to email me when it reaches a certain threshold eg:
The Kafka server I've locked down to internal use, if I open all the ports on my outbound security group I can receive the warning from the script to my email.
I would like to lock this down to a port number on my outbound security group but can't seem to do it, I've tried ports
587. I have looked around online but nothing I found to do what I need, does anyone know what port it is?