Customers find that adding Email Reputation Services to their anti-spam solutions has an exponential impact on offloading existing filtering solutions. What can appear to be only a small increase in blocked connections can translate into a large reduction of actual messages entering the filtering portion of their email infrastructure.
Translating blocked connections into blocked messages is more involved than simply applying a 1:1 ratio. Studies show that while legitimate sources average slightly more than one message per connection, each connection from a spam source contains, conservatively, an average of 1.6 messages.
It is far more efficient to reject spam at the connection level rather than take each message through full anti-spam scanning.
Connection Blocking Requirements |
Scanning Each Message Requirements |
The initial portion of the SMTP handshake |
The full SMTP-handshake |
A DNS query |
Complete message parsing, putting strains on computers that run anti-spam solutions |