Definition[]
The MAPS RSS (Relay Spam Stopper) is an extensive list of IP addresses of known insecure ("open relay") e-mail servers.
Overview[]
A third-party relay, also known as an "open relay" or "insecure relay," is an e-mail server that will route email for any third party to any other third party, no questions asked. Spammers often hunt for and abuse open relays in an effort to cover their tracks because they know their spam is unwelcome and unwanted.