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Email server behind a firewall

Started by sivakalyan, 2006-03-29T21:23:23-06:00 (Wednesday)

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I am trying to configure an email server on my linux box using postfix and dovecot. But I am behind a firewall. The email is working fine whithin my lan but no email is going outside the lan i.e. any email I send to yahoo , gmail etc. are not being sent. Similarly, when I send email from yahoo or gmail to any email on my domain, I get back a Mailer Daemon message saying that the account name doesnot exist on the domain.

Can anyone help??


William Grim

Give us network details and we can help.  Right now I know you are behind a firewall, but I don't know anything about your network topology other than that.
William Grim
IT Associate, Morgan Stanley



I have a small lan behind the firewall/router. The topology is like this:

 - Router / Firewall

 - LAN
   -- Linux Box (Centos 4.3, 2.6 Kernel)
        --- This is the machine on which I want to setup the email server. It is also the DNS and the DHCP server for our lan.

   -- Two Windows boxes
        --- These are general clients. They don't run any services.

 - Domain Name
   -- Internal : example.com
   -- External : www.sivakalyan.com

Hope this information will be useful.


Peter Motyka

First, you seem to be missing an MX record for sivakalyan.com.

I sent a message to root@www.sivakalyan.com, which will attempt to deliver mail directly to and it seemed to work ok.

Mar 30 12:55:09 eudora postfix/smtp[5087]: C7CEB97BD: to=, relay=www.sivakalyan.com[], delay=1, status=sent (250 Ok: queued as 7A947DAAD3)

Try setting up your MX record and then try sending mail to user@domain.com.
SIUE CS Alumni 2002
Grad Student, Regis University
Senior Engineer, Ping Identity