Symptoms
When using InstantForum.NET i'm receiving an error message similar to:-
The transport failed to connect to the server.
Description: An unhandled exception occurred during the execution of the current web request.
Please review the stack trace for more information about the error and where it originated in the code.
Exception Details: System.Runtime.InteropServices.COMException: The transport failed to connect to the server.
Cause
This error message will be displayed when the application is attempting to send email and is failing to establish a connection with the SMTP server you have specified in the InstantForum_SMTPServer application setting within the web.config file.
Resolution
Contact your network administrator or hosting company and request a valid SMTP server that will permit SMTP relaying. Update the InstantForum_SMTPServer application setting with this new SMTP server address.
Dave Wanta provides a list of possible extended causes at http://www.systemwebmail.com/faq/4.3.9.aspx
To test if a server you have specified will allow anonymous relaying please visit http://www.abuse.net/relay.html.
Please don't hesitate to contact support@instantasp.co.uk should you have any problems with this.