The Header and Envelope rewrite mini-HOWTO explains how to rewrite your from address differently in the mail header and the mail envelope. This may be necessary, for example, if your ISP requires you to send mail with one address, but you are subscribed to mailing lists with a different address, or want others to see a forwarding address instead of your ISP's address.
The Linux MIDI HOWTO describes the hardware, software, and procedures needed to play and sequence using MIDI under Linux. It covers configuring your MIDI interface, playing MIDI files, sequencing, controlling external MIDI equipment, MIDI-controlled software-based sound synthesis, and example MIDI code.
The Postfix-Cyrus-Web-cyradm-HOWTO document guides you through the installation of the Postfix mail transportation agent (MTA) and the Cyrus IMAP server. The goal is a fully functional high-performance mail system with user administration via Web-cyradm, a Web interface. Data like virtual users, aliases, etc., are stored in a MySQL database.