Filtering protocol verifying the sender address through authorization records made available in DNS to prevent address forgery.

An email security company offering hosted spam and virus protection and a scanning engine especially for OEMs. Also offers Exchange hosting.

Managed spam service featuring message store/forward, message archiving, and administration at both end user and domain levels.

Australian POP3 email spam filtering service requiring no software.

Managed mail service with parental controls, POP/IMAP and Webmail.

Spam filtering service to block spam and viruses by domain.

Provides redundant managed email filtering services: protection against spam, virus and failure without changes to the existing installation.

Stops spam before it reaches your network. Managed spam filtering service blocks spam, viruses, spyware, and phishing schemes. A 30 day free trial is offered.

Checks your existing POP3 email account every ten minutes and filters spam and viruses. A 30 day free trial is offered.

An open source email content filter application. Clapf is a modular statistical antispam application with an interface to popular antivirus programs.