I use the QMail-Toaster flavor of QMail. This is a package of QMail maintained by Nick Hemmesch, which is geared toward making the setup and install of a QMail mail server a little easier. The official site for QMail-Toaster is here. I liked the way thing
What this toaster does and does not do: This "howto" will walk you through building a Linux Qmail "Toaster". While these instructions are intended to work with popular Linux distributions, they will probably work on other flavors of Unix without too much
Qmail Toaster has many interesting features. Besides supporting the POP3, SMTP, and IMAP protocols, it supports the more secure POP3-SSL and IMAP-SSL. It can provide SMTP roaming for remote users using SMTP-AUTH, POP3-AUTH, and IMAP-AUTH. Qmail Toaster ha