The problem is, his internal name server is NOT his public name server. That is why he can dig internally, but externally he can't. Tony, to answer your question, yes, the problem is your ISP needs to have a PTR record setup for your mail server. ----- Original Message ----- From: "Scott Taylor" <scott@xxxxxxxxxxxxxxx> To: <linux-admin@xxxxxxxxxxxxxxx> Sent: Tuesday, August 03, 2004 12:22 PM Subject: Re: Reverse lookup problem > > Tony Gogoi said: > > > > Hello, > > > > Our mail server uses "sendmail" and DNS server used "bind". > > > > We have a problem with sending mail to a site X which returns error > > "Sender IP must resolve". So, that means their mail server could not > > reverse map our mail server's IP address to fully qualified domain name. > > > > As long as there is a reverse lookup it should be OK. Try 'host IP' to > see if you have a reverse lookup, if not, ask your ISP to add one. > Doesn't even have to resolve to your domain name, just as long as it > resolves. > > -- > Scott > > - > : send the line "unsubscribe linux-admin" in > the body of a message to majordomo@xxxxxxxxxxxxxxx > More majordomo info at http://vger.kernel.org/majordomo-info.html - : send the line "unsubscribe linux-admin" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
