Helios qmail is an advanced qmail distribution
based on qmail-sql. It has SMTP, SMTPS, POP3,
POP3S, IMAP, and IMAPS services, a content
scanner, antispoof and SPF support, SMTP-AUTH,
SMTP-after-POP/IMAP, a PHP5 API, and many other
useful tools.
Information regarding Project Releases and Project Resources. Note that the information here is a quote from Freecode.com page, and the downloads themselves may not be hosted on OSDN.