Question : SharePoint and an outsourced Exchange email

Ok i've been dealing with this issue for a few days now.

We've just recently implemented a single server SharePoint environment. Everything seems to be running fine except for outgoing email.  For example, when i add a user to a site and click the "send a notification email to them" box, i get
 
"The user or users have been added successfully, but there was an error in sending the e-mail message. The server may not be set up correctly to send e-mail. To verify that e-mail is configured correctly, contact your server administrator"

I can't get alerts on doc changes, etc either.

We do not host our Exchange. We have outsourced that to USA.net. They have given me their authenticated SMTP server as well as their Non-Auth SMTP server and neither seem to work.

I have installed the SMTP service on the sharepoint server and configured it to work with USA.net (so i think) and still nothing.

I've also set the Outgoing Email Settings in SharePoint to the same as the SMTP service setup.

Am i missing some configuration on SharePoint or a configuration on the server itself?
 

Answer : SharePoint and an outsourced Exchange email

firewall issue?  you could test with a google smart host or hotmail (if you have their accounts).  Really there isn't a whole lot to IIS smtp.

check: http://www.microsoft.com/technet/prodtechnol/WindowsServer2003/Library/IIS/6003ab51-7eb5-47b2-8d92-e26b1deeeac1.mspx?mfr=true