On 10 Aug 2006, at 19:12, Hank Nussbacher wrote:
I'll answer on-list since this answer can benefit others. The
primary reason that the ISP wants to block outbound webmail spam is
because the 100s of BLs on the Internet end up blocking large
segments of the IP space due to spam reporting by end users. The
spammer can end up "burning" quite a few IPs before the feedback
loop of user->spam report->BL->ISP->block is completed. Therefore
the ISP wants to be proactive and shut off the spam before it even
starts. Even if it means losing revenue.
This seems to imply that you're using dynamic addressing.
The rather obvious solution would seem to be that you provide static
addressing. It also makes it rather easier to identify the spammer
when the complaints come in since you won't need to grovel through
your RADIUS logs.