mailx is not working outside e-mails

HI
i wrote schell script to send e-mail automatically.
it works only e-mail for our company.say for example,
company name is : abc,
example: joe@abc.com
every body is receiving with xxx@abc.com (abc.com)
if any body from outside of our company like
joe@xyz.com.(xyz.com) are not receiving. we are using SMTP in unix server.

what could be the problem why other server e-mail groups are receiving.
is there any setting on SMTP on unix server or any firewalls setting unix server.
is there any alternate way to fix the problem.

thanks for your help
N.

I had similar issue on my Unix box. I think this is becuase of your unix server does not support SMPT of mail box. You have to approach your Unix admin to enable it.

Thanks for your reply.

If you are writing the script on SMTP server itself, check DNS working fine.

If they are diferent boxes, you must enable "RELAYing your scrpting box" on SMTP server.