User Guide

CHAPTER 2. APPLICATION
DEPLOYMENT SCENARIOS
This chapter contains a detailed discussion of the application’s architecture and
operating principles as well as typical scenarios of its deployment.
2.1. Application architecture
The review of the functionality of the application must be preceded by a
description of its internal architecture.
Kaspersky SMTP-Gateway is a full-featured Mail Transfer Agent (MTA) able to
receive and route email traffic scanning email messages for viruses. Kaspersky
SMTP-Gateway uses SMTP protocol options (RFC 2821), Internet message
format (RFC 2822), MIME format (RFC 2045-2049, 2231, 2646), and satisfies
the requirements to mail relays (RFC 1123). In accordance with anti-spam
recommendations (RFC 2505), the application uses its own relaying table to
prevent using of this application as an open relay. In addition, Kaspersky SMTP-
Gateway supports the following SMTP protocol extensions:
• Pipelining – Enhances performance of servers supporting this mode of
operation (RFC 2920).
• 8-bit MIME Transport – Processes national language characters code
tables (RFC 1652).
• Enhanced Error Codes – Provides more informative explanations of
protocol errors (RFC 2034).
• DSN (Delivery Status Notifications) – Decreases bandwidth usage and
provides more reliable diagnostics (RFC 1891, 3461-3464).
• SMTP Message Size Declaration – Decreases the load and increases
transfer rate (RFC 1870).
Kaspersky SMTP-Gateway includes the following components:
• smtpgw - the main component – a full-featured mail relay with in-built
anti-virus protection;
• licensemanager – component for managing license keys (installation,
removal, viewing statistics).