I have a bunch of domains as
relay domains at my
sendmail config, i noticed that some dirty botnet is using dns spoof to be able to send emails using those
How it works:
a domain zzz.xxx.tld resolves back to 127.0.0.1, when my server tries to resolve zzz.xxx.tld it falls back to 127.0.0.1 spoof!
Is there anyway to fix/avoid/block this? relaying only on specific server ips would be better?