Definition of spam firewall: A spam firewall is a single box computing
appliance that is set up in front of the email server. A proper spam firewall
protects the email server from all forms of attack in addition to filtering spam.
Our spam firewall blocks 95% of all unsolicited spam emails.
Below is a brief outline of our anti-spam service. Why settle on a more
costly solution when our spam solution is one of the easiest and superior spam
services out there on the market today:
Blacklisting of Web sites & domains: Final Host maintains an
up-to-date list of the largest and most aggressive known spammers. This list is
maintained by both our anti-spam network and other anti-spam groups. This list
is automatically updated on each Spam Firewall.
Keyword scanning of emails: This can be configured on a per-user
basis. Our scanning methods include a scoring system such that emails are scored
based on a number of criteria. If the score is above a threshold, then that
email is flagged as spam. Our Spam Firewall comes with default thresholds that
can be changed according to user preferences.
Checksum technology: Our network monitors email traffic via the
Internet and uses checksum technology to keep track of the number of times a
particular message has appeared on the Internet. If a message has appeared very
broadly, it would be categorized as "known spam". Checksums of known
spam messages are utilized by our Spam Firewall to block spam messages.
Message authenticity checking: Several algorithms are utilized to
verify the authenticity of a message. Some of these are simple checks to verify
that the from address is authentic. Some are more complex relating to SMTP
Blacklists and Whitelists: Domains, IPs, and email addresses can be
blocked or whitelisted (allowed through). These lists may be maintained on a
per-user or corporate basis.
Rate controls: Rate controls are utilized to stop DOS (denial of
service) attacks as well as dictionary based spam attacks. Rate controls are are
integrated and automatic in our Spam Firewall.
Spam Fingerprint Checking: Fingerprinting techniques examine the
characteristics, or fingerprint, of emails previously identified as spam and use
this information to identify the same or similar email, each time one is
intercepted. These real time fingerprint checks are continuously updated by
Barracuda Central and provide a method of identifying spam with nearly zero
Intent Analysis: Intent Analysis is used to look at the objective or
goal of the email. If the objective of the email is to sell something, (such as
click a URL) , or get the user to take a particular action that is indicative
spam, the email will be categorized as spam.