On Thu, Jun 10, 2004 at 03:20:24PM +1200, neil gardner wrote:
OK, serious thought here... Bear with me... I may be a) Describing an existing system or b) way off base.
Transparent SMTP proxy intercepts all messages and maintains a running total of emails sent per source IP. This running total is actually stored as a time distribution (ie. 10 emails in 10 minutes, then none in 10, then 100 in ten etc)
Sounds pretty complicated to me. Why not just tell all your customers you're going to block port 25 except to your mail server, and that it won't affect them unless they're doing something unusual. Those that will be affected will probably know, and they can contact you and ask for an exception. You ask a few basic questions to make sure they have some degree of clue, and open it for them. Those who are doing it and didn't know will hopefully remember that email they got, and contact you afterwards. You'd probably need to send a few emails over the month before you actually cut them off. You could also monitor who's making direct connections before all this and contact them directly, of course. Most importantly, advertise what a good ISP you're being, helping save the world from spam. Just my thoughts. Richard