On one of our AIX servers, I'm having problems sending email to an external domain. I'm not a SYSADM and not sure how to troubleshoot this issue. Any help will be greatly appreciated.
The following mail components are installed on the server
$ lslpp -l bos.mh
Fileset Level State Description
----------------------------------------------------------------------------
Path: /usr/lib/objrepos
bos.mh 5.2.0.50 APPLIED Mail Handler
Path: /etc/objrepos
bos.mh 5.2.0.0 COMMITTED Mail Handler
You should first of all try using the mailx command with the -v option to send a test email to the remote recipient. This should at least let you see if your relay host is accepting the mail.
E.g. mailx -v -s "Some subject" joe.bloggs@somedomain.com
Enter a test message and then a '.' on a line by itself to end the message. You'll then see the server attempt to send the mail using sendmail.
The sendmail configuration file is /etc/mail.sendmail.cf. View this file to see if a smart relay host is set. There are books dedicated to sendmail so I won't tell you any more about it, just ask your sysadmin 
Hope this helps a little.
Thanks for your response.
I looked into the mail log at /usr/spool/mail/voorkey and this is the error that I observed
550 5.1.2 voorkey@xxx.com... Host unknown (Name server: yyy.com.: host not found)
The id I'm trying to send a mail to an intranet id from AIX host.
I'm able to ping the host name server yyy.com from the AIX server and was also able to telnet to the host name on port 25.
My sysadm has indicated that there are no firewalls installed on this test server. I'm able to send mails to this intranet id from other development and production AIX servers. I would appreciate any pointers to track this problem further.
Thanks,
voorkey