Server Recon is a simple and effective technique developed by Sendio to stop automated spamming computer programs. It works efficiently in the background and operates in a completely independent manner relative to our IP Address Reputation technology. This results in very broad real-time email security coverage. Here is how we do it:
Sendio tracks source IP addresses for all email senders to our customers 24 hours per day. When an IP address first sends email to one of our customers, Sendio will defer the email automatically in the SMTP transaction, and then upon retry (usually a few minutes later) the sender’s message is accepted for further processing by the additional email security layers within Sendio. Once this Server Recon “handshake” is successful, the sender IP address will not undergo the Server Recon deferral again for the next 30 days. Server Recon is fully configurable by each Sendio customer, and if desired specific senders can be exempted from Server Recon completely.
In a nutshell, the vast majority of spammers are defeated by Server Recon without Sendio ever accepting their email as automated spamming systems rarely “retry” a deferred message. Good senders’ email still gets through after a an initial Server Recon event because the whole process follows SMTP email standards and conventions.
The benefits of Sendio’s Server Recon to your organization:
Brand new attacks for which no security “signatures” exist yet will never enter your network, and your users are kept safe.
Bandwidth is saved because the full emails from many spammers are never accepted.