An invalid key ({0}) was detected in the SMTPServerList Hashtable. The following keys are valid: Server: The DNS name of ...

An invalid key ({0}) was detected in the SMTPServerList Hashtable. The following keys are valid: 

Server: The DNS name of the SMTP e-mail server. This key is required and assumes a value of type string.

Port: The port number to use when connecting to the SMTP server. If a value is not specified for this key, the default value of 25 is used.

Authentication: The authentication type used on the SMTP server. The two valid values for this key are "Windows" (for windows integrated authentication) or "Anonymous" (for anonymous authentication).