Pure-FTPd is a free (BSD), secure, production-quality and standard-conformant FTP server which is actively supported and designed with security in mind. It focuses on efficiency, ease of use and provides simple answers to common needs, plus unique useful features for personal users especially on Linux VPS servers as well as hosting providers. Pure-FTPd can even run 100% non-root, with its built-in chroot() emulation and virtual accounts.
virtual-users
How to setup a mail server with virtual domains using Postfix, Dovecot and OpenDKIM
In this article we will walk you through the installation and configuration of a mail server with virtual domains and users using Postfix, Dovecot and OpenDKIM on an Ubuntu VPS. By using virtual domains and users, you can set up unlimited email accounts without creating system users. This should work on other Linux VPS systems as well but was tested and written for Ubuntu.
How to setup simple but yet powerful mail server using Postfix, Dovecot and Sasl in Debian 6 (Squeeze)
The following article aims into installing and configuring a simple POP3/IMAP/SMTP mail server in your Debian VPS using Postfix, Dovecot and SASL.
What is Postfix? It is a drop in replacement for the old and mature Sendmail. Postfix also attempts to be very fast, easy to administer, and secure.
What is Dovecot? It is an open source IMAP and POP3 server for *NIX-like systems, written primarily with security in mind.
What is SASL? SASL, the Simple Authentication and Security Layer, is a generic mechanism for protocols to accomplish authentication.