s/qmail/DOC/HELO/EHLOについて、ここに記述してください。

HELOCHECK       Meaning
""      evaluate control/badhelo
"."     reject session, if no HELO/EHLO greeting is provided/empty and evaluate control/badhelo
"="     require that the HELO/EHLO greeting corresponds to the FQDN (= TCPREMOTEHOST) of the host
"A"     DNS A lookup for the HELO/EHLO greeting and evaluate control/badhelo
"M"     DNS MX lookup for the HELO/EHLO greeting and evaluate control/badhelo