I am not sure that I understand your problem, but I will try. You said: " Last week, attempts to send mail to various corporations and educational institutions has been bouncing. The headers of our bounce notices say simply "Failed to connect to SMTP host COMPANY.COM because: Remote system no longer responding"
That tells me you are having a problem sending to others and that your system is not looking up DNS records correctly. Unless I need more coffee. That said your reply address is aspca.org, so your email goes to NY and then is routed to you in Illinois? Also, there is no MX record for mwro.aspca.org br.mwro.aspca.org does not resolve from here. No such record. 12.15.29.130 does resolve back correctly. So you that may be your issue, can't resolve br.mwro.aspca.org so you are failing circular dns checks. But that should cause a hard failure from the receiving server (if they check that) not a 'no longer responding' which sounds like a connection failure. What am I missing....explain it again to me maybe. :) > -----Original Message----- > From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] > Sent: Tuesday, August 26, 2008 3:40 PM > To: NT System Admin Issues > Subject: Perhaps a bit OT - mail bouncing > > Greetings! > > We are the mid-west office of the ASPCA (Illinois). Our HQ is in NYC. > Our > wires, DNS, etc are via AT&T. Their wires, DNS, etc are through > QualityTech. As NY is the parent office (to say nothing of older and > bigger), the QualityTech system is the SOA for ASPCA.ORG. For the > Illinois public addresses (including the IP address stamped onto all > our > outgoing email), we have NS records on the QualityTech system pointing > our > network (mwro.aspca.org) to the AT&T name servers. All had been well > the > past several months... > > Last week, attempts to send mail to various corporations and > educational > institutions has been bouncing. The headers of our bounce notices say > simply "Failed to connect to SMTP host COMPANY.COM because: Remote > system > no longer responding" > > One company told us it is because the IP address is not resolving > properly... > > I have checked the DNS tables for QualityTech, and they do show "mwro" > being delegated to a pair of AT&T DNS servers. I have checked the DNS > tables for AT&T, and we do have records in both forward and reverse > lookup > zones (br.mwro.aspca.org <-> 12.15.29.130). > > Any ideas (while I wait and wait and wait to talk to AT&T)? The Boss > suggests the "fix" for last month's "DNS Poisoning" might have "fixed" > things so that anything claiming to be from [anything].aspca.org must > resolve to a QualityTech address and not to an AT&T address. Still, I > don't see that we can do much to fix this... > > We are considering using a VPN tunnel to try to use a NY machine as an > outgoing SMTP server. What else might we try? > > Other folks experiencing this? > > Thanks!!!!! > -------------------------------------- > Richard McClary, Systems Administrator > ASPCA Knowledge Management > 1717 S Philo Rd, Ste 36, Urbana, IL 61802 > 217-337-9761 > http://www.aspca.org > > > ~ Finally, powerful endpoint security that ISN'T a resource hog! ~ > ~ <http://www.sunbeltsoftware.com/Business/VIPRE-Enterprise/> ~ ~ Finally, powerful endpoint security that ISN'T a resource hog! ~ ~ <http://www.sunbeltsoftware.com/Business/VIPRE-Enterprise/> ~
