We currently have Sniffer running as a SpamAssassin plugin on a BSD box. This server is acting as a gateway for inbound email and we have been very pleased with the results.
We are re-evaluating our setup in light of a lack of BSD/Linux/Unix experience in our staff and are looking for suggestions. We would like a windows based solution for a gateway. The following features are greatly desired: .Message Sniffer (of course) .Recipient verification (may be based on a text file of valid addresses or query of the backend server) .Greylisting .Integration with SpamAssassin would be ideal .Virus scanning is also required. ClamAV or the like is fine for our needs. We have a relatively low message volume, and cost is a consideration. Thanks, David