Generally, the interaction test is performed with manual Telnet mail server 25. But now I have a URL to help me test:
http://www.abuse.net/relay.html
Just enter the IP address of your mail server, it will automatically carry out more than 4 times, and finally conclude, such as:
This May Or May Not Mean That it's an open relay.
.
You cannot TELL IT IS Really An Open Relay WITHOUT SENDING A Test Message; This Anonymous User Test Did NOT SEND A Test Message.
