[lug] Stopping the New Generation of Spam

[Daniel Webb]

On Mon, Dec 04, 2006 at 03:23:17AM -0700, Sean Reifschneider wrote:

> On Sun, Dec 03, 2006 at 07:16:51PM -0700, Daniel Webb wrote:
> >The nice thing about greylisting is no silent false positives.
> 
> That's not entirely true.  There are plenty of mail servers that are not
> "greylisting compatible".  Some sites will retry sending from different IP
> addresses, others that run mailing lists will change the sender address for
> bounce detection...  Those can cause issues with greylisting.
> 
> Though, yeah, in most cases greylisting works great with very little
> training required.

But assuming the SMTP server isn't totally broken, the sender's mail server
will send them a bounce message letting the sender know that the message
didn't go through, right?  The ones that scare me are the "silent" ones where
the sender sends the email, SpamAssasin tags it spam and I delete it without
looking at it.  The sender has no way to know that their message was deleted
as spam.  With greylisting, they should get a bounce so that they can contact
you another way.  Same if you move all spam filtering to SMTP-time: the sender
always knows if their message was not delivered.  I like that property a lot.