Microsoft Outlook 2003 and 2007: Built-in Junk Software


Microsoft Outlook 2003 and 2007: Built-in Junk Software

As the reader probably already know the latest versions of Microsoft Outlook 2003 and 2007 have built-in Junk E-mail Filter. Here we are going to talk about how it works, its advantages and disadvantages. When the user sets a certain level of anti-spam security, Outlook starts to analyze new incoming messages as soon as they arrive to Inbox. By default Junk E-mail Filter is set to Low level, which means that only obvious spam is filtered out. There is also High level of security, when Outlook thoroughly checks incoming messages and moves all the suspicious messages to Junk E-mail Folder. We would recommend you to try the Low level first, to see if it works correctly, and only then switch to High.

Although it is impossible to customize the algorithm used in Microsoft Outlook for spam detection, you can help Outlook improve its performance by creating a list of safe senders and blocked senders. A safe senders list contains e-mail addresses from which all messages will be received in Inbox and never marked as spam. Obviously, the other list consists of addresses and domains from where you expect only spam and all messages coming from these addresses will be treated as spam.

Analyzing an incoming message Outlook Junk E-mail Filter goes through the following steps:

  • Checks if the address is from Address Book assuming that all messages from any such address are legitimate,
  • Checks if the address is from GAL list that contains only addresses, from which you want to receive letters,
  • Checks if the address is from Safe Senders List, which is made by the user and contains the addresses trusted by the user,
  • Checks if the address in "To:" field of the message is from Safe Recipients List where the user keeps e-mail addresses of distribution lists or newsgroups which he/she is subscribed to,
  • Checks if the address is from Blocked Senders List and moves all messages with addresses from this list to Junk-Email folder,
  • Scans the contents of the message in order to detect spam. Spam detection filter is trying to find certain features, which are typical for spam messages, and based on this, rates the message on a scale of 1 to 100. The higher is the rating the higher is the probability that this message is spam. Afterwards the message is moved to either Inbox or Junk-Email folder depending on which anti-spam security level is chosen by the user. Being set for the High level Outlook will filter out all the letters with ratings above some quite low threshold while if the Low level is set then only highly suspicious messages with high ratings will be sent to Junk-Email folder.

After all, it is very sensible to check your Junk-Email folder from time to time before emptying it to insure that no important messages have got there. There is a possibility that the chosen anti-spam security level is too high and sometimes Outlook moves some legitimate messages to Junk-Email folder. If Outlook quite often filters out messages from a certain legitimate correspondent then this problem can be solved by adding the address of this correspondent to Safe Senders List.

How Blocked Senders List and Safe Senders List can help in reducing the amount of spam is quite clear while the purpose of introducing Safe Recipients List is not that obvious. Actually, Safe Recipient is a mailing list, a distribution list or a newsgroup that the user is subscribed to. A subscriber of the list cannot control membership but can assume that the administrator doesn't allow spam to be distributed within the list. So to avoid losing messages form a certain list the user should inform Outlook about this by adding the address of the distribution list or the newsgroup in Safe Recipients List.

Unfortunately, even the most complex contemporary anti-spam technologies cannot guarantee absolute security and there always be spam messages that manage to get through the filter. However if the user is patient enough it is possible to improve anti-spam security. Adding to Blocked Senders List all the addresses of the spam messages that escaped Junk E-mail Filter will gradually increase Outlook's ability to detect and filter out junk e-mail.

Finally, please notice that Microsoft Outlook Junk E-mail Filter works on the client and the filter can be activated only if Outlook is set to Cached Exchange Mode regime or by connecting to POP3 or IMAP4 servers (using these protocols assumes that messages are downloaded to local storage for further handling).

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About the Author: Mike Grunch, Tech Writer at LuxContinent.
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