Wednesday, May 21, 2008

Three and the spam problem

So if you've been keeping up you'll know I have one of Three's new HSDPA USB modems on loan for review, and that I'm also currently out in Italy.

After sorting out some teething troubles, the SIM card I have didn't come pre-activated for international roaming since it's a trial account, I've been using it fairly heavily. There is actually good coverage out here in Trieste, better in fact than I've seen in the UK in the past. Transfer speeds are pretty good, it's only noticeably slower than WiFi when you hit something like Google Maps which is heavy with AJAX and dynamic content.

I have stumbled across one problem though. Interestingly, it looks like the email I'm sending when connected through the dongle is getting black holed by the SpamCop, SORBS and NJABL lists.

Looking at the SpamCop entry for the pool address I was using it has been listed 17 times for a total of 69.4 days in the last 71 days. Most the other IP addresses in the same block have also been listed. In other words, it looks like a lot of Three's dynamic IP pool is listed as a source of spam.

That's bad news. Certainly anyone who sent me email that got flagged as coming from an IP address which is on one, or in this case more than one, real-time blackhole list stands a poor chance of me ever actually seeing the message unless they're on my mail client's white list. Since my white list basically consists of my boss and my wife, and not necessarily in that order, it's unlikely that will help them that much.

Of course I can work round the problem by connecting to my work's VPN, which means that to the world it'll look just as though I'm sitting back at my desk in Exeter. However, not everyone has that option. While black listing addresses in dynamic IP pools isn't entirely without controversy, it's fairly common practice. It looks like Three needs to clean house...