Framework for publishing information through DNS describing a list of ip addresses allowed to send emails from a specific domain.

Spam reporting service.

Focuses on identifying, classifying, tagging and monitoring legitimate email.

Email management solution that provides full control over security and usage of corporate email systems.

Collaborative spam filtering network allowing users to report and filter out matching spam.

An email filtering service for businesses or individual domains. 30 day trial offered.

Free antispam service for pop, Yahoo, and Hotmail accounts supporting multiple languages.

System of clients and servers that collect and count checksums of email messages in order to detect and filter bulk UCE.

Open source collaborative spam filtering system using digests of messages to identify spams.

Offers protection against spam, combined with personalization and privacy for individual email users.