On 11/15/2017 9:48 AM, P.V.Anthony wrote: > Hi, > > My postfix server was rejecting emails from the following server. I > think it is because I am using "reject_unknown_helo_hostname". > > ------------------ start ------------------ > Nov 15 13:20:13 mail postfix/smtpd[14663]: NOQUEUE: reject: RCPT > from unknown[103.230.232.100]: 450 4.7.1 <DD1HMALPPPPT02.hmail.sg>: > Helo command rejected: Host not found; from=<fromname@fromdomain> > to=<toname@todomain> proto=ESMTP helo=<DD1HMALPPPPT02.hmail.sg> > ------------------ end -------------------- > > From the helo, I can see DD1HMALPPPPT02.hmail.sg. But this domain > does not resolve, as you can see bellow. So comes my question, is it > complulsory for an outgoing smtp server to have a fully qualified > domain name. With an "A" record. > > If it is not complusory then my setting was too strong and I really > should remove "reject_unknown_helo_hostname".
It is not required. I used this for a while here with warn_if_reject and it appeared to catch more legit mail than spam. -- Noel Jones
