February 24th, 2006 at 03:04pm
If the number of people landing here by searching for information about the Bigpond Gmail block, and the number of other websites discussing it is anything to go by, Bigpond’s Gmail block has been quite an ordeal throughout the week.
It turns out that Bigpond use somewhat overzealous third party server blocklists that attempt to automatically work out which SMTP servers are open for third party use, and effectively spamming. Technically this should put just about every ISP mail server on the planet on some blocklist by virtue of the fact that you don’t have to be connected to your ISP to utilise their mail servers.
The basic fact of the matter is that this is an outdated method of blocking mail servers, as most spam originates from “botnets” created on home PCs by malware. These botnets are sold to spammers, “malicious users”, etc by malware programmers for a profit, this is fairly effective as it allows standard PCs, which look pretty innocent, to sporadically start sending spam and other useless junk all over the place.
Unfortunately, one of Gmail’s servers was incorrectly picked up by one of these blocklists late last week, and Bigpond then picked it up in their semi-daily or thereabouts update. Gmail’s server was removed from the list sometime this week, and Bigpond worked that out today at about 11am Canberra Time (Midnight GMT).
There is still a bit of a delay as the queued mail gets delivered, but services appear to be back to normal. Incidentally, another ISP, iinet if my memory serves me correctly, fell fowl of these blocklists a couple weeks ago, and have just recently been fixed.
The bottom line is, Bigpond are now accepting emails from Gmail, and probably blocking someone else instead. I have some advice for Bigpond, forget blocklists, use some proper anti-spam technology to run checks on incoming mail, there’s some pretty good open source software that does precisely that, and it will do a much better job than overzealous blocklists.