If you have to accomodate wildcard (unknown) IPs, there's no way to restrict by IP. IMail does not allow you to reject messages for local virtual hosts. The tactics you can use, in order of preference, are:
Is there a way to get iMail to insert SMTP AUTH info into the header? If so I could potentially set up a processing rule that looks for either the accepted IP's or the AUTH accepted string...
-Jeff
