Block non local domain relay mail.

[teerasak]

How can I block non local domain relay mail to my server ? or
Can I limit sending hosts by message count ?
My customer's network being hacked by spammer, mulware or spyware. Then send relay spam mail to my server that their source ip is relayhosts. So they can relay mail spam to my server.

Thanks,
Teerasak

[thewebhosting]

Kindly check the IP address from where you are receiving the spam emails and block that particular IP address on your server firewall.