03/04/2010

We are testing on all of our internal SMTP servers a new service called SpamSentinel Reputation. It is designed to stop about 60% of traffic at HELO, reducing bandwidth and server CPU utilization significantly. It is mostly designed to immediately stop "zombie" computers, which send 100% spam. This means there will be no false positives from this service.

Those messages that are not from 100% spam sources get processed via SpamSentinel, examining content as well as worldwide email patterns.

As this is designed to improve SpamSentinel, there is no additional cost for this software for existing customers. Our first rollout is to customers who process more than 50,000 messages per server per day. This service acts effectively like an "appliance" but without the extra hardware or the false positives.


Here is a sample from our main inbound SMTP server (our SMTP 10 record):

SS Reputation blocks 60% of messages at HELO, The remaining messages, about 44K are processed by SpamSentinel on the server, filtering off 99.2% of the 60% that remain. The overall block rate is 99.63% (397/107,661)

Most of these messages are from zombie servers. The net result is 60% reduction in bandwidth and saving server CPU.



Overall block rate is 99.63%