emergency!! my postfix server cant resolve!!!

[gwu]

emails are not able to send out. i get an error in maillog saying "...cant fing host..." no matter where we send to!!! However, when i ping, the names are being resolved!!

 

[pupu]

What exactly is the message you get? Try to use 'dig <hostname>' from your postfix server. If it won't resolve, check /etc/resolv.conf (list of resolvers).

 

[gwu]

&quot;name service error for aol.com: host not found, try again&quot;
&quot;name service error for yahoo.com: host not found, try again&quot;

I now know what caused the problem but i dont know why. Recently i put our DNS server on another server on another LAN. it looks like the problem started when i shutdown the old dns server and started using only the new dns server. However, i updated my /etc/resolv.conf file to reflect the new changes when i switched to the new server but for some reason the postfix system cannot resolve the email hosts to be sent to. I fixed it by setting the old nameserver ip address in resolv. But why didnt it work???

old /etc/resolv.conf:
********
nameserver 205.91.104.3
********


new /etc/resolv.conf:
********
nameserver 200.157.2.6
nameserver 200.157.2.4
********

 

[bluegroper]

Not sure if this helps but, have you included a valid (or changed the ?)
relayhost = your.isp.mail.server.com
in your postfix main.cf ?

 

[pupu]

That cannot cause it. Are you really able to resolve using new dns server? Try 'dig @200.157.2.6 aol.com -t any'. Maybe there is a firewall in the way (do you have iptables active? or some PIX between networks?)