Mail send problem, reverse lookup not possbile

Dear Sir, Madam,

This is one issue I do not understand en that I cannot repair myself without help. Some customers where complaining that they couldnt send email to particular partys. When looking further, i saw the message in SendmailQueue from Postfix server: 1.33 kB host[] refused to talk to me: 451 Temporary local problem - please try later

When looking further, looking in your docs, I tried: host (=my server) Reult:Host not found: 2(SERVFAIL) or When I use other nameservers in /etc/resolv.conf Host not found: 3(NXDOMAIN)

I have several domains on one IP and probably I misconfugured some dns setting In the ISP dns I programmed this ip to go to this virtal server Websites work correctly but sending mail does not deliver, or gets in spam boxed.

Please help me, I would be very thankful! With regards,

Bas Huijsen The Netherlands

What am I overlooking, or what should I do to correct this problem.



You need to contact your ISP or hosting company about this - typically they control the reverse DNS entries for customer systems, and can most likely set yours to whatever you want.

Howdy -- well, to setup reverse DNS for a given IP address, you can contact your ISP to handle that for you.

Now, concerning other DNS issues -- you can always use a DNS service such as to perform a DNS check for any of your domains.

When entering the domain "" into there, it mentions that one of your listed nameservers, (, didn't respond. That may be contributing to the problem.