mailx not working

i am supporting a server running Solaris 5.6.I don't know if the mail is configured on this server.

i ran the following commands and got the corresponding output.

#which mailx
/usr/bin/mailx
#ps -ef | grep sendmail
    root   601     1  0   Jan 10 ?        0:01 /usr/lib/sendmail -bd -q15m
  ncmops 21668 21634  0 18:58:53 pts/0    0:00 grep sendmail

from the above outputs i thought that mail is configured on this server
so i tried to run the following command

mailx asalman.qazi@gmail.com
Subject: Test
This is a test mail
EOT

in the above command i tried to change the email address to my organizations email address but still the mailx is not working
I am in doubt that is the mail really configured on this machine.
I some body can suggest a way to find that out.Please tell any logfiles
or output i need to mention here for that investigation.
If the mail is already confiured (which in this case seems yes) Then
why i am not able to send any mails

Thanks in advance

Do a mailx -v to each address and compare the differences.

This has been covered before in:

http://www.unix.com/unix-advanced-expert-users/127099-sendmail-works-gmail-but-not-my-company-well-clients-domain.html
which might help.