Yesterday I wrote a short comment about the Spamhouse case. Spamhouse is indeed very important as an antispam blacklist. However, for my server I can only state that since I moved to it (previously my domains were hosted together with other domains on a server managed by a German hoster) greylisting works amazingly well for me. In fact I did not have a single spam mail through my domains since I use greylisting. And not that you think I do not get many attempts from spammers – the frequency is something like one mail per minute.
Greylisting, however, eliminated all spam to these domains from my mailbox. It seems my mail provider does not use greylisting. Is it that greylisting requires a second connection attempt and that the mail queues of my mail providers SMTP would simply be too small to bear the spam and legit mail server connection attempts? It would really be interesting. In fact GMX – my mail provider – advertises with the following sentence
Unschlagbar: Deutschlands bester Spamschutz (Testsieg PC Magazin 10/2006)
which translates to “Unbeatable: Germanys best spam protection (Winner in test by PC Magazin 10/2006)”. This is a little strange since I still get a reasonable amount of spam through these channels. No, this time I will not blame them for it, I just wonder which technical reason keeps them from using greylisting (yes, I tested whether they use greylisting and they don’t 😉 …).
I believe the same holds for other big mail providers as well. Anyone out there who reads my blog and can comment on this?