Maine State Government

Dept. of Administrative & Financial Services

Office of Information Technology

 

BEST PRACTICE USING SOFTWARE FILTER TECHNIQUES TO MINIMIZE DELIVERY OF COMMERCIALLY UNWANTED ELECTRONIC MESSAGES THROUGHOUT MAINE STATE GOVERNMENT

I. Statement

The Office of Information Technology will employ filtering techniques to identify and tag suspected SPAM. Users can use local rules to manage the disposition of tagged messages.

II. Purpose

The purpose of this Best Practice is to document various software filter techniques and methods used by the OIT to implement the Policy to Minimize Delivery of Unwanted Commercial Electronic Messages throughout Maine State Government.

III. Applicability

This Best Practice applies to the Office of Information Technology (OIT); and it will impact all agencies of Maine State Government which use the Office’s email and other electronic messaging networks.

IV. Responsibilities

A. The OIT will enable filters on the State’s SMTP servers’ anti-spam software using word lists and the Bayesian Filter.

B. Individual State employees may direct tagged mail into a separate folder of their Outlook client mailbox by applying a rule if they choose to do so.  See the References section for rule application instructions.

V. Guidelines & Procedures

A. For all incoming SMTP messages, OIT’s email servers will be configured to first analyze them via the Bayesian filter and then check them against the word list.  A BEST PRACTICE message will be tagged if it meets criteria specific to either filter.  Once tagged, the email message will be delivered to the recipient’s mailbox.

B. Individual employees can manage tagged e-mail messages at the client level by invoking an Outlook Rule, which is used to transfer messages to user designated folders (e.g. the spam folder or Deleted Items folder). 

VI. Definitions

 

1.      Bayesian Filter - The process of using Bayesian statistical methods to distinguish email that is statistically likely to be spam, from email that is most likely to be legitimate.

 

2.      Tag - The application, by anti-spam software of specific marking, such as [subj_ADV] placed on the right side of the subject in the subject line of an e-mail message, to identify an email message as probable spam.  Tagging helps email recipients quickly determine if a message is wanted, or unwanted.  By the application of rules, individual email recipients can route tagged messages to a (delete) folder for action at their convenience.

 

3.      Word Filter - Method of selecting messages of which the subject line contain words in a list.  OIT’s list is composed of universally offensive words.            

 

4.      Simple Mail Transfer Protocol (SMTP) - SMTP is the de facto standard for e-mail transmission across the Internet.

 

VII. References

 

1.      Instructions for managing tagged mail at the client level:  http://inet.state.me.us/oit/services/electronicmessaging/index.html

 

2.      Policy to Minimize Delivery of Unwanted Commercial Electronic Messages throughout Maine State Government http://www.maine.gov/oit/oitpolicies/index.htm

 

VIII. Document Information

 

1.  Document Reference Number:     3.2

 

2.  Category:     Internet, Network and Transport

 

3.  Adoption Date:     August 10, 2006

 

4.  Effective Date:     August 10, 2006

 

5.  Review Date:     August 10, 2009

 

(1)               6.  Point of Contact:     Sandra Saunders, Maureen Tuttle and Lori Blier, Enterprise Messaging Team, Applications Services, Office of Information Technology

 

7. Approved By:     Richard B. Thompson, Chief Information Officer

 

8.  Position Title(s) or Agency Responsible for Enforcement:     Kathy Record, Associate Chief Information Officer, Office of Information Technology

 

9.  Legal Citation:

 

10.  Waiver Process: