This HowTo will describe the setup of an efficient http server and mail server for small or medium configurations (as low as 96 mb). So this config is ideal for a small VPS. You can find a good choice of cheap and performant VPS (XEN) at x|encon, a german hosting company. they provide many scalable VPS solutions with pre-installed Debian and Ubuntu disc images.
Why LEMP instead of LAMP? NGINX is a great replacement for Apache with very low memory footprint and great stability.
Note: i will use the name yourdomain.com for all configurations on a fresh minimal installation of Ubuntu Feisty Fawn server edition.
We will have to install first Postfix to deal with emails and then Dovecot to deliver them with pop3 only (imap uses too much memory). But before that, let's install some useful tools we need: