I read John Peach's response to a mail regarding the Postfix option to reject non-FQDN HELO transactions.
http://www.irbs.net/internet/postfix/0302/0183.html He states that Joris Benschop is correct in that email. I was scanning through RFC 821 (and also through RFC2821 which has superseeded it) and I cannot find the quote referenced in the message above in either of those documents. Where can I find an official reference which validates what he stated in the message above? As far as I can tell, section 5.2.5 does not exist in in RFC821 and section 3.5 does not contain the quote specified in the above mentioned message. I used these references to verify the content of the RFCs. http://www.ietf.org/rfc/rfc821.txt http://www.ietf.org/rfc/rfc2821.txt http://www.faqs.org/rfcs/rfc821.html http://www.faqs.org/rfcs/rfc2821.html The main.cf options I'm referring to are these: http://www.postfix.org/postconf.5.html#reject_non_fqdn_helo_hostname http://www.postfix.org/postconf.5.html#reject_unknown_helo_hostname Apparently RFC2821 also allows IP-adress syntax (see section 4.1.1.1). Can someone enlighten me as to what is actually correct behaviour according to RFC? Regards, Robin Smidsrød
