Topic: E-mail sending error

[Ismar]

I have GNAT Box Fire wall installed and internaly Web/Email E-smith configured as xxx.com
If I sent E-mail with use of SMTP server as mail.xxx.com the error comes up and Server reponses 551 Sorry ........ I dont allow unautorized relaying......
If I setup SMTP to be my local IP address of this server 192.168.0.11 it works fine.
If I try to use mail.xxx.com from outside with any other ISP it still doesn't work

I also have a another E-smith Server/Gateway setup (I dont use GNAT Box) with which I can do all this without problems and with using www.xxx.com as SMTP Server from inside or outside.

I tryed using all posts related with this issue to resolve the problem but no luck.
I dont know if this is an problem of E-smith or GNAT box.

Please help me anybody
Thank you.

[chris meredith]

My guess would be that when you try to access the SMTP server by name mail.xxx.com DNS redirects you to the external interface of your NAT box.  That may then pass the External IP to the SMTP server, which probably isn't configured to allow relaying from that IP.  When you connect by IP it passes a local IP.  To test you could add an entry to your hosts file so that mail.xxx.com resolves to its internal IP.

As for you other box, it sound like you have relaying enabled for internal and external hosts, which isn't the best idea.

You might want to look into using POP before SMTP, which would allow you to relay from anyplace that had succesfully logged into the pop server.

http://forums.contribs.org/index.php?topic=13476.msg51146#msg51146

I have several offices using one mail server, and even a Palm Phone user.  Works for all of them.