MDaemon
Released on October 24, 2006. Features included:
Backscatter Protection, and Custom Mail Queuing.
Available in the following 13 languages:
English, German, French, Spanish, Russian, Japanese, Portuguese, Italian, Chinese, Dutch / Netherlands, Swedish, Polish, Thai
Released on October 29, 2002. Features included:
Tarpitting, and WorldClient (Web-Based Email Client) - Secure Socket Layer (SSL) Support.
Account Quotas, Sender Blacklists, Aliases with Wildcards, Automatic Mail Forwarding, Configurable Mail Port, Protocol Timeout, and Session Inactivity Values, Configurable Storage Locations, Easy to Backup and Restore Via Flat File Structure, IP Screening and Address Suppression, IP Shielding, Mailing Lists (Digests, Subscribe/Unsubscribe Support, Moderator Options, Post-Only / Read-Only Access, and Archiving), Out-Of-Office Auto-Responder, Real-Time Session Activity Logging, Simplified (On / Off) Message Archiving to Public Folders or to Designated Email, Address(es), SMTP Greeting "Site Policy", SMTP, POP3, MuliPOP, and Delivery of Mail Directly to Recipients' Mail Server or to Your Smart Host.