ISMail is easy to set up at home or in the office. Features include multiple domains, unlimited mail accounts, account quotas, mailing groups, antispam content filters, antivirus scanners, IP-based access control, open relay protection, SMTP authentication, statistics, Windows services, vacation responders, and log files.

Online help is available for testing network and server configuration. An uninstaller is also included.

Download: ISMail 1.5.1
Source: Instantservers