SMTP probes

["Brian Jameson" <tech () jameson co uk>]

I am getting a steady stream of probes on port 25 to my honeypot(thp). I
would like to investigate these further and re-call sometime ago a
discussion on this list about software(linux based) that responded to the
first couple of e-mails and then tar-pitted or blocked subsequent calls.
Needless to say I now can't find those e-mails! Therefore recommendations
would be appreciated from list members on software to tackle this issue.
Thanks in advance for your thoughts.

regards,
Brian