On 15/01/2008, at 11:40 AM, Chris Curtis wrote:
I presume you do have a spam product doing a good job?
Personally I am more concerned with getting the stuff blocked than reducing incoming traffic, as traffic is cheap these days. Also, spam messages are typically small, and therefore 90% of messages doesn't equate to 90% of traffic. We've got a product here doing an excellent job. 1 or 2 a month are slipping through to my inbox, and I've never had a false positive I know about.
This said, I don't deal with enterprise size deployments, so therefore don't have to watch every bit of bandwidth like a hawk.
It is not the bandwidth that we worry about, it is the processing capacity. Currently we have three grunty boxes handing incoming mail and doing anti-spam processing. With out grey listing we would need at least another one and without spam at all we could get away with two much smaller machines. Our current worry is that spammers will suddenly decide that greylisting is taking too much of a toll on their operations and rewrite their senders to include some crude queueing. Then we would have to handle nearly double the number of incoming messages. I believe that this could happen quite quickly and we would be left with heavily overloaded incoming mail servers as it takes *at least* a month from order to deployment of new hardware. More realistically two months as these are not off the shelf components. Russell