AOL lifted a block on email from ISP Demon yesterday, after a sudden surge of spam messages provoked AOL into rejecting all email from Demon users last Friday.
In a notice to its users on Friday, Demon admitted that its users were unable to send email to a "small number of other ISPs" because of measures introduced after spammers used open mail relays within its network to send bulk email. No-one for Demon was available for comment this afternoon, so we not sure which ISPs other than AOL were involved.
Demon (probably correctly) attributed the problem to misconfiguration of its customers" machines, a point to which we"ll return presently. AOL has an in-house automated system which blocks emails from individual IP ranges or in some cases, an entire ISP, if these are identified as the source of a spam onslaught, a company spokesman told us.Spam last week from Demon reached such levels that the AOL introduced a temporary block to stem the deluge.
AOL has now restored connectivity to Demon.While the root cause of the problem is insecure configuration by its users, Demon has an obligation both to educate its customers on the problem and to actively scan its network for open mail relays before the problem gets out of hand.