Configuring IIS 6.0 to send mail via SMTP for asp.net applications

Michael Nichols — Thu, 08 May 2008 05:29:21 GMT

Enabling smtp services for IIS is well documented, but configuring in my environment was more difficult than I would have thought it would be... So this post is partly a note for me as we will be changing out gear soon.

Our environment is not very exotic...a box acting as an web server, and another box acting as an exchange server. Both are running Win2003.

First, smtp services must obviously be enabled/running. Here is how.

Next, in IIS, select the new SMTP Virtual server node and right-click/Properties/Access/Relay. Be sure 'Only the list below' is selected and add '127.0.0.1' (localhost) to your Computers Access list . Finally, deselect 'Allow all computers which successfully authenticate...'. Be very careful not to turn your server into a relay server unless you like being blacklisted .

Now, at this point I was able to get my mail sent to domains outside my own. So if my webserver was webbox.mydomain.com and it sent mail to mygmail@gmail.com then all worked just fine. But I was unable to send mail internally to other mail accounts (mydomain.com).

What I failed to do was set up a SMART HOST to route mail to my exchange box.

To do that, right-click the smtp node in iis/Properties/Delivery/Advanced. Enter the name of the server hosting exchange and deselect 'attempt direct delivery before sending to smart host'.

Mike Nichols - Son Of Nun Technology : Email

Configuring IIS 6.0 to send mail via SMTP for asp.net applications