Qpsmtpd, like qmail-smtpd, doesn't insist on HELO having a parameter. If a lazy tester (such as myself :)) just types HELO, then SMTP.pm complains of an undefined reference when logging, and generates a Received header which Spamassassin can't parse as it doesn't match their qpsmtpd RE.
RFC-2821 does not accept HELO/EHLO from being sent without a parameter. The sending server may send something other than domain name (the spec says it SHOULD be an address literal othewise), but the standard is clear that something must be sent. The BNF is clear (RFC-2821, 4.1.1.1):
Syntax:
ehlo = "EHLO" SP Domain CRLF
helo = "HELO" SP Domain CRLFI'd rather fix this by requiring a parameter than by glossing over it, even if it means breaking strict compatibility with qmail-smtpd.
John
