Question : Exchange 2003 SMTP Problem - I'm a newbie

Hello:

I am trying to learn how to deploy Exchange 2003 properly.  I have installed W2003 and Exchange 2003 on a server.  I honestly have no idea what I am doing when it comes to exchange.

I have an Internet domain that I want to setup for email.  No need for anything internal.  Through trial and error, I was able to get the server to accept incoming mail, but it refused to send.

I learned that my ISP was blocking port 25.  My solution was to forward my mail to the ISP as a smart host.  I configured that in the Internet Mail SMTP Connector.

Now, I tried setting up an Outlook client to be able to POP/SMTP.  When I tried to send mail, I was getting it back as undelivered.  The error message was, "550 5.7.1 Unable to relay...".  I checked MSKB article 260973, which said that I should "click to select the 'allow messages to be relayed to this domain' check box on the Address Space tab in the connector properties".  I did, and I got a warning message telling me that I was essentially opening myself up to be an open relay.  I continued, and now my email is working properly through the client!!  This is very frustrating!

I want to secure this server so that it can't be used as a relay.  What can I do to meet both of these needs?

Answer : Exchange 2003 SMTP Problem - I'm a newbie

ok, relax :)

http://www.microsoft.com/technet/prodtechnol/exchange/2003/library/default.mspx

Everything you'd want to know. Secondly, with an exchange server facing the internet, it has to allow ALL connections, but allow NO relaying. this is configured by default, in the SMTP VS in the Exchange System Manager. Unless you have a server or IP specifically granted relay permissions, then you're not open for relay. You could also clear the checkbox which allows any computer to relay if it authenticates. If this breaks mail flow, then enter the Exchange server's Ip address to the relay field, so it can contact itself to send mail

 For additional security, use a front-end server for SMTP, this will allow you to tighten Exchange a good deal. you'll like this better in the "real world"

D