Security Assurance Appliance  Spam Blocker

Block Spam at the Network Gateway

TheFree Spam Blocker uses advanced spam filtering to block spam at the gateway before it ever reaches the users.  ZerZero client installations and an intuitive GUI make it easy for administrators to:

  • Leverage the best spam filtering techniques including Bayesian Filters, Razor, realtime block lists (RBLs), OCR for image spam and tarpitting
  • Provide individual quarantines for each mailbox
  • Filter SMTP, POP & IMAP

Spam is the bane of small businesses’ existence. It can not only bring viruses onto your network, but it can take over your computers and send spam to other computers.

And it impacts you in other ways. According to a recent study, the cost of spam messages to U.S. companies—in terms of productivity and the equipment, software and manpower to combat it—was upwards of $10 billion in 2004.

So the key is to stop spam before it stops you.

Our powerful Spam Blocker protects you with top-notch spam scanning and blocking at the edge of your network—before it can do damage or slow you down. Using the latest technologies, Spam Blocker transparently scans for spam, marks messages and intercepts emails. It requires no alteration of your network’s mail configuration and is constantly updated to guard against any refinements in trickery or techniques that senders create to get around other solutions.

Key Features:

  • Open source & free under the GNU General Public License (GPL)
  • Quarantine Digest—our Spam Blocker is optimized to make sure “good” mail is never mistaken for spam. However, if a “good” mail is ever identified as spam, Untangle Spam Blocker gives each team member in your company their own personal “quarantine” list. They can find that email without having to track down an administrator
  • Personal Passlist—users can designate certain email addresses as “good” without having to bother your IT person
  • Image based filtering — scans images within emails to stop this new type of spam
  • POP, IMAP & SMTP support
  • Reports give a comprehensive view of the spam environment on your network, including the source of the spam and how much spam is received in aggregate and by user

Spam Blocker Technical Specifications

Spam Blocker is an intelligent email filter that identifies Spam—unsolicited bulk email. Spam Blocker can scan any email that is transported by the following protocols:

  • SMTP
  • POP
  • IMAP

Each protocol has a set of controls to customize how Spam Blocker:

  • Scans for spam
  • Notifies users of spam
  • Manages spam

Through the user interface, you can define the threshold that instructs Spam Blocker to be strict, lenient, or somewhere in between. To handle the spam, simply use the properties that Untangle Server provides to instruct Spam Blocker to take any of the following actions:

  • In the subject of the email, insert the phrase [Spam], and allow users to filter spam to a special folder.
  • Send the message to the recipient without labeling the email as spam
  • Block the message without notifying the recipient that the message was blocked, and record this action in the Event Log
  • Quarantine the message so that you or your users can investigate spam and take further action
  • Notify the sender that the email was blocked
  • Withhold notifications

Under the Hood

Spam Blocker implements a rule-based architecture that leverages the open-source project SpamAssasin. No one rule can flag email as spam. It's the collection of rules that identifies email as spam. Each rule outputs a confidence level. The combination of each rule's confidence level produces a spam score. This score identifies the likelihood that the email is spam. The user-defined threshold you use to customize Spam Blocker's scanning sensitivity is based on this score.

What It Does

Transparently scans SMTP, POP and IMAP traffic and blocks, quarantines or marks spam

How It Does It

Uses SpamAssassin, Razor, Bayesian filters, DNSBL/RBLs, optical character recognition (OCR), tar pitting, custom tuning and updates

Controls
  • SMTP: Can quarantine, mark, pass or block incoming and outgoing with or without sender notification
  • POP and IMAP: mark or pass incoming and outgoing (the nature of POP and IMAP protocols prevents messages from being blocked or quarantined, but they can be scanned and marked)
  • Global and per-user safe lists and quarantines
  • Browser-based user tools for managing individual quarantines and safe-lists
  • Scan strength adjustable per protocol per direction