SPAM Filter ISP's implementation is very simple. Its use is recommended for ISPs and companies running their SMTP server, not end-users. SPAMFilter ISP is designed to be the spam filter gateway to your incoming SMTP server. 

SpamFilter ISP receives all emails addressed to your domain(s) and uses several different filtering methods to detect spam in emails. Spam-free emails are then forwarded to your SMTP server(s) (see SPAM Filter's details here). End-users have web access to view their own quarantined emails. An optional anti-virus plugin is available to stop email viruses.

SpamFilter ISP's strength lies in the large number of filters that are applied to detect spam. Examples are:

Images embedded in emails are scanned for spam
SFDB - SpamFilter's new distributed blacklist database.
The sender's IP is listed in one or multiple DNS-based block lists.
The Bayesian statistical analysis of the email suggests it is spam.
The SPF spam filter authenticates the sender to ensure their address is not fake.
All of the URLs in the email are tested using the SURBL filter.
Individual countries can be blocked as wanted.
The sender's DNS MX mail records are tested for a correct configuration.
Email content is tested by the Spam Filter server against user-defined keywords (RegEx - Regular Expressions are supported by most filters).

Please look at the "how SPAM Filter ISP works" details for more information on our anti spam filter server and on all of our additional anti spam features.