This is a distribution based on Qmail but not covered by Dan Bernstien's guarantee. The code and features added to this version is based on using software engineering methods to optimize performance on business and ISP class email servers.
- optional reverse dns existance check for MTAs (not for customer MUA)
- optional windows greylisting for MTAs
- vpopmail user validation (check user)
- clamAV Anti Virsus scanning for all email via simscan
- DSpam (learning based) spam content filtering via simscan for MTAs
- clustering via mysql backend
- smtp TLS (encryption over standard smtp port 25)
- SSL support for pop3, smtp and imap on standard ssl ports
- SquirrelMail webmail with Calendar support and custom skin
- Calendar Server
- Historical Email Traffic Graphs
Note: MTAs or Mail Transfer Agents are the remote email servers that are sending mail to a local customer account. MUA or Mail User Agent are the email programs that customers use to send and receive mail, like Mozilla Thunderbird.