SpamAssassin Rule: RCVD_IN_SORBS_SMTP
Standard description: SORBS: sender is open SMTP relay
Explanation
This check tests the IP address of the last untrusted relay against the DNSBL maintained by SORBS.
A listing indicates that email may be sent through a SMTP proxy by an unauthorized and unauthenticated user.
Further Info
The default scores for this rule can be found in the online list of tests.