[TriLUG] posting

[Aaron S. Joyner]

Rick DeNatale wrote:

>For those of us who use things like gmail, which no doubt use email
>server farms, it might take a while for all of those ip addresses to
>get greylisted.
>
>In other words the "you" in "the first time you send a message to the
>list." is a bit fuzzy in these cases.
>
>At least it looks like the mail will get a soft bounce, and not a hard bounce.
>  
>
Intelligent mail systems (like Gmail, presumably) will send your message 
to one of a dozen or more "outgoing" smtp relays.  That message then 
gets queued up on that machine for delivery, and that one machine is 
responsible for the final delivery of that message.  Each delivery 
attempt will come from that one machine, with it's IP address.  This is 
by far the easiest way to scale this solution, as it only requires a lot 
of boxes, and one round-robin DNS entry.

Less intelligent systems may do as you fear, and have one large queue, 
and any of a dozen machines can pull out the message and send it.  Not 
only is this method more difficult to implement, it's much messier and 
has a central point of failure (that big central queue).  As the 
popularity of greylisting spreads, people will stop doing brain-dead 
things like that.  :)  Most of them already have.  In the very unlikely 
case that turns out to be a problem, we have the flexibility to add 
exceptions to the grey-listing, based on IP address or IP address range, 
which allows us to work around the stupidity of others.

Aaron S. Joyner