SPF record in the domain DNS tree level is the new tool to combat email spam that trying to forge or spoof sender SMTP MAIL FROM and Return-Path from your domain zone. However, incorrect or misconfiguration of SPF definitions may lead to email been discarded prematurely, bounced and not delivered to intended recipients. Thus it’s good practice to test, verify and validate to ensure the SPF policy does not erroneously cause outbound emails to fail and unaccepted by relay mail server.