Hi Christian,
Apparently Gmail does not use greylisting. They can do that because they
a *massive* mail base to learn from. For smaller organisations
greylisting works very well but indeed it can take a long time for mail
to arrive.
I no longer use greylisting but when I did I had expressions
I use ASSP since years and also the greylisting. I know its a big part
to block spammers.
Many of my customers ask me why they get emails from web registrations
(shops, forums) only after hours. If you register with a Gmail address,
you will receive the confirmation after 1-2 minutes. I can not
