Chapter 1. Background

Table of Contents

1.1. Why Filter Mail During the SMTP Transaction?

1.1.1. Status Quo
1.1.2. The Cause
1.1.3. The Solution

Here we cover the advantages of filtering mail during an incoming SMTP transaction, rather than following the more conventional approach of offloading this task to the mail routing and delivery stage. We also provide a brief introduction to the SMTP transaction.