Abuse.net relay testing – www.abuse.net/relay.html
Open Relay Database Test – ordb.org/submit/
Open Relay Test – members.iinet.net.au/~remmie/relay/
Anonymous Relay Test – www.antispam-ufrj.pads.ufrj.br/test-relay.html
Anonymous Relay Test – www.aupads.org/test-relay.html
Securewall Relay Testing – www.securewall.co.uk/Forms/openrelaytestform.asp – must register
Test your mail server for an open relay – www.truson.biz/services/spam_tester.php
Third Party Relay Check – www.rbl.jp/svcheck.php
Open Relay Tester – www.mob.net/~ted/tools/relaytester.php3
SpamHelp.org SMTP Open Relay Test – www.spamhelp.org/shopenrelay/
ทดสอบ relay อื่นๆ: http://spamlinks.net/prevent-secure-relay-test.htm