Quicker Email Delivery – December 20, 2010
We are now using dnswl.org's mail server whitelist to bypass greylisting, which means that for known legitimate mail servers (all 101,686 of them at the moment), greylisting will be bypassed, which means that your e-mail will arrive a little bit sooner.We'll eventually turn off spam filtering for those servers with the "high" rating, which should mean that advertisements from companies that you've actually signed up for will be less likely to arrive in your spam folder. (things that you've actually signed up for aren't considered spam, and anyone on the whitelist with a high rating should honor unsubscribe requests quickly, or else they will lose their rating if reported)
The main feature that you might notice now is that when you sign up on a website that requires an activation email, you will get that email immediately (if they've registered to be on the whitelist) rather than having to wait for the greylisting period to expire. This example is the only down-side of greylisting that we know about. Greylisting currently blocks 10% of the incoming spam. 30% of those emails that are blocked are from "real" mail servers (it is not known whether they are spam or not) and so cause the mail to just be delayed, and not blocked).
The new whitelisting feature should cause that 30% number to go down.
Happy emailing!