SpamAssassin rule
KHOP_HELO_FCRDNS
HELO name does not match reverse DNS
+0.4 points
Combination of other tests (meta rule)
What KHOP_HELO_FCRDNS means
The name the server used in HELO is different from the reverse DNS name of its IP address.
The rule's description in SpamAssassin: “Relay HELO differs from its IP's reverse DNS”
How to fix it
Make HELO, reverse DNS (PTR) and the forward A record of your mail server all use the same host name.
Does your email trigger KHOP_HELO_FCRDNS?
Send it to a free test address: we run SpamAssassin, check SPF, DKIM and DMARC and show every rule with a fix.
Open the email spam checkerRelated rules
FORGED_GMAIL_RCVDGmail address sent through non-Gmail servers
FREEMAIL_FORGED_REPLYTOFree-mail Reply-To on a different From
FREEMAIL_FROMSent from a free email address
FREEMAIL_REPLYTODifferent free-mail addresses in From and Reply-To
FROM_FMBLA_NEWDOMFrom domain registered in the last 7 days
FROM_FMBLA_NEWDOM14From domain registered in the last 14 days
FROM_FMBLA_NEWDOM28From domain registered in the last 28 days
FSL_HELO_NON_FQDN_1HELO is not a full host name
HEADER_FROM_DIFFERENT_DOMAINSFrom and envelope sender use different domains
Frequently asked questions
What does KHOP_HELO_FCRDNS mean?
The name the server used in HELO is different from the reverse DNS name of its IP address.
How do I fix KHOP_HELO_FCRDNS?
Make HELO, reverse DNS (PTR) and the forward A record of your mail server all use the same host name.
How many points does KHOP_HELO_FCRDNS add?
0.4 points in the default SpamAssassin ruleset (network tests on, Bayes off). A message is treated as spam from 5.0 points. Mail servers can change scores locally.