Mail Filter Service:
Viruses, SPAM, & Attachments

Spam and viruses have reached epidemic proportions, but as a Biz Net customer you no longer have to be a victim. Biz Net has developed an email filtering service that intercepts all domain mail before it arrives at the final mail server to be distributed into users' email accounts.  When the email arrives at our fully redundant servers, it is checked for allowed attachments, embedded scripts, viruses, and SPAM, then processed appropriately and delivered to the intended destination.  

We can provide this service for any domain(s) by simply having your DNS zone file changed to send email to our special filtering servers.  It is recommended that our customers configure their mail server to speak exclusively to our filtering email servers. This adds an extra layer of security-- an email firewall, essentially. 

The optional settings for this service apply at a domain level and not at individual user level settings. 

What it does and why it is valuable:

1. Attachment Filtering  - Our system pre-filters all virus capable files and email formats before even checking for viruses. All viruses depend upon email attachments or MIME headers which can, by simply being viewed, cause virus code to execute on your computer. By limiting the "allowed" attachment types, we eliminate 99+% of all executable attachments. Frankly, there is NO reason for email to contain windows executable attachments. If one needs to send or receive an "exe" program type file, for instance, it should be sent as a zip file. 
   
   During one month in 2002, we filtered 1,937 messages that were KLEZ virus variant. This occurred before any virus signatures were checked!!  When the "Frethem" virus, a klez-alike, struck we captured it over 2000 times before virus sigs were udpated! Proof that our system works heuristically. 
   
   Many of our clients love having the ability to specify which types of attachments can be delivered to their employees. Some even prefer to filter out picture files, like jpegs and gifs,  just to cut out those cutesy little "joke" pictures that can waste valuable time, printer supplies, and bandwidth.    
   
   Each organization may also choose to limit the size of acceptable attachments which are allowed to be passed on  to the users. 
   
   Customer OPTIONS:
   list of each type of attachment to allow
   optional size of allowable attachments
   
   Click here for more info on Attachment Filtering
   
   

2. Virus Filtering  - We then check all "allowed" attachments against the very latest industry standard virus signatures.  Microsoft Outlook, Outlook Express, and other email clients are capable of executing various types of dangerous html code, such as Java and ActiveX. We sterilize all such code before it gets to the end user. This also catches many new viruses which aren't in the virus signature files yet, a feature most other anti-virus software lacks. You no longer have to depend solely upon your users or administrators updating their own virus signatures. Many of our corporate customers implement both their own in-house server-based virus systems and add our system as a complementary safety layer. 
   
   Customer OPTIONS:
   none: If the attachments are allowed they are virus checked. If the message has embedded code in the body or headers it is "cleaned".
   
   

3. SPAM Filtering - Also known as Unsolicited Commercial Email (UCE) filtering, the service first checks all email against a list of known open-relay systems and refuses mail from them. This cuts down on a large amount of SPAM before it ever gets to our Spam Rating System (SRS).  The SRS scans all the routing headers and label headers as well as the body of the email and looks for SPAM heuristic characteristics. It then assigns a weighted scale score to each identified characteristic found. The numerical total of these scores is compared against a threshold value. If the numerical total exceeds this threshold, one of three options are available: The organization has the option of three threshold sensitivities, HIGH, MEDIUM, and LOW to choose from. From current testing, the Medium (the default) setting seems to catch 90+ % SPAM and is recommended.  
   
   (A) We clearly identify the message as SPAM (in the subject field) and headers are added to the email and sent on to the intended recipient. Most of our clients prefer this method of delivery. The end user becomes responsible to simply create a "filter" in their email program which sends SPAM to its own inbox or deletes it upon arrival.  
   
   (B) Optionally, SRS can be configured to send all SPAM rated email to a specified email account at your domain. Your system administrator can check this box occasionally or it can be an open box for all users to check. 
   
   (C) We can also configure the server to delete SPAM. This is not recommended as there is no way to recover mislabeled email. Although it is rare, miss-labeling does occur.  
   
   Customer OPTIONS:
   
   Threshold level for SRS: HIGH, MEDIUM, LOW
   Send it on as addressed, send it to specific email address, remove to bit bucket.
   Click here for more info on SPAM Filtering
    

Pricing:

We bill for the Mail Filtering service based on the number of email accounts per company. If a company has multiple domains all pointing to the same set of user mailboxes, we charge only for one domain, but filter all of them. We must charge for additional destination servers, or virtual servers at the same rate. Our mail filtering service typically costs about $1/month per user account with a minimum $20/month charge per organization. Special discount pricing is available for Biz Net's existing customers and larger organizations.  Please call or email us for an exact quote.

For more information about our services, please contact Biz Net Technologies.