I'm using a Python smptd server on an AWS instance. It's listening on localhost, port 25. I can send mail to it through a Python smtp client on the same instance. I have an elastic IP associated with the instance. I'm calling that IP address 54.xx.xxx.x
.
When I try to send from my laptop like this:
echo "Hello" | mail -s "Test" info@54.xx.xxx.x
I get a bounce:
Final-Recipient: rfc822; info@54.xx.xxx.x
Action: failed
Status: 5.1.3
Diagnostic-Code: X-Postfix; bad address syntax
The security group for the instance has port 25 open:
How can I debug this?