A lot of my email has not been arriving, so I contacted my ISP, Tesco, which replied that it is blocking emails from Wanadoo, Yahoo and Hotmail because they are sources of spam. I agree with the principle, but why didn't they send out a warning message? Friends and I wasted a lot of time trying to resolve a problem that did not actually exist, and presumably others have, too. Bill Gill
I have had letters about mail blocking from Christopher Clifton, a Tesco.net user, Harry Mitchell (Tiscali.co.uk), Colin Killick (Freeserve.co.uk), and several who now can't send email to NTL users. Sometimes mail is returned with a message such as "host smtpin.ntlworld.com [81.103.221.10] refused to talk to me" or it just vanishes. (Tesco.net is run by NTL, and Freeserve is run by Wanadoo.)
This is not spam blocking or filtering. NTL and other ISPs are using databases provided by Sorbs (Spam and Open-Relay Blocking System) and other services that blacklist mail servers and IP addresses. All mail from those servers is blocked. Once blocked, only the ISP can get its servers removed. When I checked Sorbs on Monday, two of Wanadoo's mail servers were blacklisted (193.252.22.157 and 158) and one (193.252.22.156) was not. Mail can go through any server at random, which explains why some mail goes through while some does not.
NTL can apply what blocking list it chooses, and I expect that blocking remote servers in the US and China can block millions of spams while affecting few users. However, I would expect a rational ISP to whitelist some "nearby" servers that are the source of large amounts of legitimate mail, whether on Sorbs or not. NTL says: "It is one our highest priorities to work with block-listed ISPs to help them secure the necessary delisting. We are currently doing this with a major UK ISP."
Under the circumstances, I've been sending NTL users invitations to Gmail. However, anyone using an email address supplied by any ISP should think about moving to an independent email service. Ideally, buy your own domain name so your email address is independent of the service you are using. It's painful having to change address - but you will likely have to do it eventually, and it's better sooner rather than later.
Update: Obviously I raised the issue with NTL, with little apparent success. However, the day after this answer went to press, NTL emailed me to say it had tackled the problem. NTL's email says: "When it became clear that Wanadoo would not be de-listed in short order both NTL and Wanadoo looked for alternative ways to manage the blocked mail. NTL made system adjustments so that it was able to ignore certain block list entries, while retaining controls on the many transient and offensive spam sources that are listed for good cause. This allowed Wanadoo to send mail from all their servers to NTL customer addresses and the backlog was quickly cleared."
I trust this is the case, and thankyou NTL.
