MJ Ray wrote:
James Freer jessejazza@yahoo.co.uk wrote: [...]
AOL, yahoo and gmail seem fairly good for controlling spam and viruses from what i can gather.
Excuse my surprise, but where did you gather that and how much are AOL, yahoo and gmail paying them?
I think it's down to the definition of "good". It is, after all, pretty easy to completely eradicate spam altogether; just dump all email to /dev/null (or bounce it). Of-course 100% spam reduction doesn't sound so good when you also have a 100% false positives rate.
Once you start to take the false positives seriously, a drop in spam performance is inevitable. From what I can tell - and somewhat inevitably for a free service that has to pay for server capacity, processing, bandwidth, etc - the likes of Hotmail and Yahoo accept a higher level of false positives in order to achieve a higher level of true positives. Therefore blocking any server which has any hint of suspicion is a great tactic: you reduce spam by a large amount, and when you dump legitimate email you can blame the sender for using an account blocked for sending spam.
Then, by ignoring mails to postmaster@ etc, they get to pass the support problem on to the sender's provider(s). Result: a more manageable service, that most people will put up with given the price.
In defence of Gmail I haven't yet had any issues to deal with from the sender's side which can be laid at their door. Yahoo I don't have much dealing with at all, but BT Connect I do (largely the same thing nowadays) and get problems there. Hotmail/MSN and AOL are the worst though (anecdotally).