Question : Domain of Sender Address Does Not Exist...

I am using PHP to send e-mail through Sendmail.  Specifically, I am using the mail( ) function.  I have been using this function for years on a web host, but now I am trying to use my own server.  (Slackware Linux 7).

When I send a message, it is not delivered, and I get a message in my root mailbox stating, among other things, the following error:

"  ----- The following addresses had permanent fatal errors -----

    (reason: 501 5.1.8 ... Domain of sender address
[email protected]t does not exist)"

Do I have to set something up in order to send mail from my Linux box?  For instance, do I have to set up an SMTP server?  If so, how do I do that?  I'll give 300 points for anyone who can help me out!  (If you live close, I'll even buy you a pizza!)

Answer : Domain of Sender Address Does Not Exist...

Presumably the bounce message you've quoted is the result of you trying to send to [email protected]?

It looks like the rr.com mailserver is configured not to accept emails unless the domain of the sender exists in the public DNS. Iserver.nth-design.net doesn't exist in the dns database, which is why it's being rejected. That's a common and sensible configuration, so you need to do something at your end to resolve the problem.

To solve this problem, you could

(a) if iserver.nth-design.net has a static public ip address, make sure that it is in the dns properly.

(b) if iserver.nth-design.net has a dynamically allocated public ip address, then you could investigate adding it to the dns using a service like www.dyndns.net.

(c) you could reconfigure your sendmail so that it masquerades the [email protected]t address as [email protected]. Or you could try running your PHP script as a non-root user, and seeing whether sendmail is already masquerading. (You have to take special steps to masquerade root, even if other users are already being masqueraded by sendmail).

(d) You could find an smtp server that is on the public dns which is willing to relay your mail, and just get your sendmail to transfer all your outgoing mail to that server.

Do any of these sound feasible, given your circumstances?

Vijay