[lug] Stopping the New Generation of Spam

[Daniel Webb]

On Wed, Dec 06, 2006 at 03:48:08AM -0700, Sean Reifschneider wrote:

> Yes, but that bounce message may show up as much as 4 days later, depending
> on the sending server configuration.

Good point.  

This could actually be a point in favor of non-greylisting STMP-time
classification.  If the classification says spam, the SMTP sender will get a
permanent failure message which, under any sane scenario, would result in an
immediate bounce message to the sender.  Greylisting, as you point out, could
lead to a very long delay because it is a temporary failure that might be
repeated for days before a bounce in the case of sender with rotating IPs etc.