AddDigestSubscriber: Adds a digest subscriber to the specified list
o Return Type: GenericResult
o Parameters:
• AuthUserName: User name used to perform this function. Requires system
administrator or domain administrator privileges
• AuthPassword: Password for the username
• DomainName: The domain name for which to modify the list
• ListName: Name of the list to modify
• Subscriber: Email address to add to the digest list