Section 4.1. Introduction
Section 4.2. Configuring a Backup Mail Server in DNS
Section 4.3. Configuring Multiple Mail Servers in DNS
Section 4.4. Configuring Mail to Go to One Server and the Web to Another
Section 4.5. Configuring DNS for "Virtual" Email Addresses
Section 4.6. Configuring DNS So a Mail Server and the Email It Sends Pass Anti-Spam Tests
