I made a small event daemon a few months ago to catch this kind of spam. It will add headers to the message during the SMTP transaction that later on can be used for filtering or to trigger SpamHalter.
First a X-Identical header will be added, and then, if a number of additional conditions are met (not authenticated, not known local LAN, only one RCPT, not already blocked), a X-Blocked header will be added as well. Furthermore, if the RCPT is not a valid local user, the SMTP connection will be terminated and the sending host will be added to the short-term blacklist. Sending several such messages in sequence from one IP will cause the same action. All actions are logged to console window and log file.
The daemon can be downloaded here: http://83.140.29.200/rcptcheck.zip
To install it, copy the DLL file to your Mercury directory and add this line to the [Daemons] section in DAEMON.INI:
RcptCheck = rcptcheck.dll
/Rolf
<p>I made a small event daemon a few months ago to catch this kind of spam. It will add headers to the message during the SMTP transaction that later on can be used for filtering or to trigger SpamHalter.</p><p>First a X-Identical header will be added, and then, if a number of additional conditions are met (not authenticated, not known local LAN, only one RCPT, not already blocked), a X-Blocked header will be added as well. Furthermore, if the RCPT is not a valid local user, the SMTP connection will be terminated and the sending host will be added to the short-term blacklist. Sending several such messages in sequence from one IP will cause the same action. All actions are logged to console window and log file.</p><p>The daemon can be downloaded here: http://83.140.29.200/rcptcheck.zip</p><p>To install it, copy the DLL file to your Mercury directory and add this line to the&nbsp;[Daemons] section in&nbsp;DAEMON.INI:&nbsp;</p><p>RcptCheck = rcptcheck.dll</p><p>&nbsp;</p><p>/Rolf&nbsp;</p><p>&nbsp;</p><p>&nbsp;</p>