Problem with sending emails outside of own domain.

Greetings;


Whenever I try to send emails from my local domain to my gmail; I get an error

Code:

Jun 19 20:13:56 ubuntuserver postfix/smtpd[3150]: NOQUEUE: reject: RCPT from localhost.localdomain[127.0.0.1]: 451 4.3.0 <*********@gmail.com>: Temporary lookup failure; from=<[email protected]> to=<*********@gmail.com> proto=ESMTP helo=<[192.168.21.120]>

How come I'm getting this error? 451 4.3.0 Temporary lookup failure.
Tried googling already and it didn't really help.

I set up my Ubuntu-server using The Perfect Server - Ubuntu 12.10 (Apache2, BIND, Dovecot, ISPConfig 3) Howto
Sending emails within my own domain is no problem!

Kind regards;

Ellis

 

what's the output of

Code:

 postconf -n | egrep -i -e "mynetworks|relay_domains"

 

DNS settings?

Also the contents of your /etc/resolv.conf would be helpful. Can you ping outside domains from the server CLI?

 

Already found the problem; sorry for making an unnecessary thread!

 

i hate when people say they found the problem but don't say what was it

 

Yeah it's pretty annoying for future Googlers with the same issue haha...

Without knowing any details, my suggestion would be to check resolv.conf and dig the DNS server for the relevant records.