Hi all
Not sure whether is right forum to ask....
I am trying to resolve the problem with SMTP. When we're trying to send an email using our Web application it fails with error: "The server response was: 5.7.1 Unable to relay for <some email address>". The application is installed on IIS7 of Windows Server 2008 R2, but SMTP is on the Windows Server 2003 and IIS6. I have already read through recommendations what to do with this error and did the following:
1. SMTP Server does not have any restrictions - it is our testing SMTP. Relay option has the All computers allows and "All except the list below" option list is empty
2. Windows Server 2008 internal firewall has the port 25 opened
3. Application pool is running under domain user, which has Admin rights on both machines.
4. I also wrote the Windows client application and run it from Web Server, where the Application sits. It has the same code and settings, but works ok and manages to send the email.
It looks like the IIS7 or Web application has some restrictions or settings, which does not allow the emails to go out :( Do you have any idea, where I can have a look.
Thanks in advance for your help