Scam-grey is a milter which filters mail originating from MS Windows hosts.

Scam-grey is a milter which filters mail originating from MS Windows hosts. Scam-grey filter provides you the ability to mitigate the flow of unwanted email from such hosts using grey listing.

How it works:
On the first delivery attempt from a Windows host, Scam-grey generates a temporary error message. Subsequent delivery attempts made after the delay period will be allowed through. Unlike standard mail servers, virus, trojan infected hosts and zombies are not designed to retry the delivery after a temporary failure.

Scam-grey pairs

the helo string
the IP address of the sending server (host)
as a record and returns a temporary failure (SMTP code 450 extended code 4.7.1) if the host is greylisted.

The record is expired if there is no connection for the matching record within the next 24 hours. Click here to see a sample of mail servers which are currently greylisted

Requirements:

· sendmail version 8.12.x or higher
· You should have the milter library and development kit installed
· P0F

What's New in This Release:

· The SMTP message has been changed to show the actual delay for the connection.
· A feature has been added to make logging less verbose.
· The ASN lookup now takes precedence over the regular expressions used for whitelisting.