jonathan dill qcovkbaqnerdsnet get thought postfix complaining host lookup fqdn match ip honest looks like someone owned server bit fun server literally announcing spamserver helo instead fqdn telnet 6422240195 25 trying 6422240195 connected 6422240195 escape character 220 spamserver microsoft esmtp mail service version 6037901830 ready fri 8 feb 2008 165539 0800 sandy drobic wrote jonathan dill wrote james parra wrote suggest client ask clients vantage point server one rejecting mail need tread politely concerning removing reject_non_fqdn_hostname reject_non_fqdn_helo_hostname something want werent client wouldnt worry much must way could add exception maincf domain ip address sent email server would also reject would alone seriously wonder setting etcnsswitchconf check files first adding entry etchosts would fix eg 6422240195 nsky3com sure postfix verifies fqdn uses os resolver stack method client hostname rejected helo name client determines announces receiving server especially stupid since configure helo system kick admin server nonfqdnhelo whitelist client tue 05 aug 2008 190906 0500 server rejecting mail single domain