Managed Anti-Spam

The Network Box anti-spam solution is the most comprehensive and effective gateway anti-spam solution in the market today. It provides 24 anti-spam engines, combining over a dozen different techniques and is backed by a vast database of anti-spam signatures. It provides true defense-in-depth, in a single managed gateway appliance.

The Network Box Anti-Spam email gateway achieves an industry-record 97.5% detection rate, with almost zero false-positives.

Some of the solutions deployed by Network Box are:       

• Co-operative spam checksums 
  This technique involves breaking apart a message, and taking cryptographic checksums of each component of the message. 

• Signatures and spam scoring
  Lists of "signatures" which match aspects of spam messages.

• Whitelists and Blacklists 
  Lists of words / patterns which make a message "ham" (good email) or "spam".

• Heuristics 
  By examining behaviour, tests can be designed to determine if an email is spam.

• Real-Time IP Blacklists
  Lists of gateways known to be either:  
  • known sources of spam
  • known open-relays (allowing third-party relaying of messages)
  • known dial-up networks

• Real-Time URL Blacklists
  Lists of URLs used by spammers

• URL to IP Mapping and Blacklists
  Lists of IP addresses used by spammers

• URL Categorisation
  Using the on-board SurfControl database, URLs can be categorised

• Domain Age
  If a domain is very young this can be an indicator of spam.

• Bayesian Filtering
  Statistical (or Bayesian) filters can be used to automatically maintain word / pattern white lists and blacklists, together with statistical probabilities as to whether the given word / pattern makes the message spam/ham.

• Challenge / Response Systems
  Network Box can challenge previously unknown senders to check they are not spammers.

• Digital Signatures
  This technique is normally used to indicate that an email message is "ham", and is not used to determine spam.

• Optical Character Recognition (OCR)
  Spams sent as pictures can be interpreted as text and hence detected.

Anti-Spam Configuration

The Network Box email system is extremely configurable. Individual engines can be enabled/disabled based on tests, including:

• Direction of the message (inbound or outbound)
• Whether the message is being filtered (for example, POP3, IMAP4)
• Whether the message is redirectable (for example, SMTP)
• Globally (that is, for everything)
• Based on the content of a message headers
• Based on the proxy handling the message (for example, SMTP, POP3)
• Based on a single recipient of the message
• Based on a recipient being one of the recipients of the message
• Based on the sender of the messages
• Based on the sender IP address
• Individual engine parameters can be set to adjust scores and weightings to suit end-user requirements.