Not sure if this could be the problem....but <http://www.samspade.org/t/refer?a=80.162.200.77> 80.162.200.77 has valid reverse DNS of 0x50a2c84d.unknown.tele.dk <http://www.samspade.org/t/refer?a=0x50a2c84d.unknown.tele.dk> The results of your other IP seem ok. <http://www.samspade.org/t/refer?a=80.197.127.239> 80.197.127.239 has valid reverse DNS of gw01.subcore.dk <http://www.samspade.org/t/refer?a=gw01.subcore.dk> -----Original Message----- From: David Elmquist [mailto:david@xxxxxxxxxx] Sent: Monday, February 24, 2003 10:07 AM To: [ExchangeList] Subject: [exchangelist] Exchange not receiving mail from some domains http://www.MSExchange.org/ Hi list I have a somewhat peculiar problem with inbound mail. Some mails, especially those from this very list, never reaches my Exchange server, but are always recieved via my mx backup server. I can`t see any connection attempts from the sending servers, so at first i took it to be a DNS related problem but now i`m not so sure. subcore.dk MX preference = 10, mail exchanger = gw01.subcore.dk subcore.dk MX preference = 20, mail exchanger = gw02.subcore.dk subcore.dk MX preference = 15, mail exchanger = mail.subcore.dk gw01.subcore.dk internet address = 80.197.127.239 mail.subcore.dk internet address = 80.197.127.239 gw02.subcore.dk internet address = 80.162.200.77 Generally, mail is delivered to gw01, but some mailservers just don`t seem to want to talk to it. This has been a problem for over 2 months now. I don`t think network problems could be responsible for the problem. Perhaps filtering at the ISP could account for it, but both servers are on The same cablesegment, although not the same IP subnet. Any ideas as to how I should troubleshoot this ? David Elmquist b ------------------------------------------------------ List Archives: http://www.webelists.com/cgi/lyris.pl?enter=exchangelist Exchange Newsletters: http://www.msexchange.org/pages/newsletter.asp Exchange FAQ: http://www.msexchange.org/pages/larticle.asp?type=FAQ ------------------------------------------------------ ISA Server Resource Site: http://www.isaserver.org Windows Security Resource Site: http://www.windowsecurity.com/ Windows 2000/NT Fax Solutions: http://www.ntfaxfaq.com ------------------------------------------------------ You are currently subscribed to this MSExchange.org Discussion List as: dufoem@xxxxxxxxxxx To unsubscribe send a blank email to $subst('Email.Unsub')