ANS Spam Plus utilizes
three layers of protection to analyze each piece of
email and to detect and act on suspected spam.
Blacklisting: ANS uses a proprietary
blacklist. We do not use commercial blacklists such
as MAPS and ORBZ/S. Most commercial and public blacklists
follow a "guilty until proven innocent" approach,
which frequently blocks email from legitimate senders.
Our blacklist contains only the addresses of the most
egregious spammers on the Internet. While conservative,
our blacklist can immediately block nearly 10 percent
of our customer's inbound spam.
Fingerprinting: Messages not blocked
by blacklisting are fingerprinted to detect matches
with known spam message characteristics. ANS's fingerprinting
technology leverages knowledge gained from filtering
mail for our entire customer base. The fingerprinting
database aggregates data from all spam blocked by our
system allowing the fingerprinting process to become
more intelligent and refined as more mail is processed.
Messages identified as spam are fingerprinted and
given a unique id based on their content. If these
messages come through our system again, the fingerprint
is detected and the message is marked as spam.
Messages are analyzed to determine new spamming methods (i.e., base64-encoded
spam). Once determined, a dedicated spam team modifies our scoring layer on
the fly to catch spam using the same method.
Rules-based scoring: Scores are assigned
to messages based on more than 20,000 rules that embody
and define characteristics of spam and legitimate email.
Points are added to the score if a message contains
characteristics of spam; and points are subtracted
if it contains many characteristics of legitimate email.
When a message's score reaches a defined threshold,
it is flagged as spam. Message characteristics we evaluate
and score include:
- Phrases in the body and subject of the message
- Formation of headers (i.e., Message-ID, Received,
random characters)
- Originating mail server / Originating mail agent
- From and SMTP From address
Spam Treatment
Most customers choose to quarantine messages identified as spam outside their
network. Quarantined messages are stored and deleted after 15 days. Customers
can review quarantined messages and retrieve improperly blocked messages through
SpamShark, a Web-based tool.
Unlike most competitors, ANS Spam Plus has a very
low incidence of blocking legitimate email - less than
one for every 250,000 emails received (less than 0.0004
percent).
As an alternative to quarantining messages, ANS Spam
Plus also allows spam to be sent through to customers.
When ANS Spam Plus forwards spam, it can modify the
message to flag it for internal review. Modifications
can include:
- Inserting an X-header for filtering inside the
perimeter
- Inserting a new subject line message (i.e., < This
is spam >)
- Directing spam to an internal SMTP mailbox
Benefits
Automatic spam filtering – No user interaction is required;
and it is not necessary to set up of individual accounts
Highly accurate filtering – Legitimate
business email is not blocked.
No white listing – Highly granular
and accurate spam filtering technology eliminates the
need to white list approved mail senders.
Hassle-free quarantine – Spam
quarantined in SpamShark can be reviewed through the
Web-based SpamShark interface; quarantined spam automatically
expires after 30 days and is deleted.
Improved network efficiency – Eliminating
spam outside your network reduces the load on mail
servers and results in network usage and storage savings.
Contact us today to learn
more about ANS Spam Plus. |
