Sendmail 8.13.3 Securing Mailing Solution

Executive Summary
This white paper discusses the STARTTLS and AUTH features that are supported in
Sendmail 8.13.3. It also describes how to configure these features on HP-UX systems,
to provide an effective secure mailing solution. In addition, this white paper includes
selected usage models and examples, and discusses the benefits of using these Sendmail
8.13.3 features on HP-UX systems. This whitepaper also describes how to create a
Certificate Authority (CA) and to prepare or sign certificates for Sendmail 8.13.3 servers.
Intended Audience
This white paper is intended for HP customers who are using or planning to use
Sendmail 8.13.3 to ensure mail security. This white paper is also intended for system
administrators, HP support personnel for Sendmail 8.13.3, HP field engineers, and
consultants who advise customers on security solutions. Readers of this document
must be familiar with using Sendmail 8.13.3.
Introduction
Sendmail 8.13.3 is the latest version of Mail Transfer Agent (MTA) available on the
HP-UX operating system. It offers enhanced security, performance, and anti-spamming
capabilities.
Following are the salient security features of Sendmail 8.13.3:
• Transport Layer Security (TLS)/Secure Sockets Layer (SSL) support
• CyrusSASL support
This white paper describes how to configure these security features in Sendmail 8.13.3.
This white paper addresses the following topics:
• “TLS/SSL Support” (page 9)
• “Cyrus SASL Support” (page 12)
• “Configuring Sendmail 8.13.3 with TLS and SSL” (page 13)
• “Configuring Sendmail 8.13.3 with SASL” (page 22)
• “Verifying the Cyrus SASL Setup” (page 28)
• “Related Information” (page 28)
TLS/SSL Support
Sendmail 8.13.3 uses the Transport Layer Security (TLS) and the Secure Socket Layer
(SSL) to encrypt not only the user name and password, but the entire mail transmission.
To signal the beginning of an encrypted TLS conversation, Sendmail 8.13.3 uses the
STARTTLS command within an SMTP conversation.
STARTTLS feature is an extension of the SMTP service that enables an SMTP server
and client to use the transport layer security in providing private and authenticated
Executive Summary 9