Updated: 24 September, 2000

Pegasus Mail Anti-Spam Measures

(How to Get Rid of Junk Mail, Spam, and Telemarketers)

Pegasus Mail now incorporates anti-spam features. The following statement has been released by Pegasus.
The use or distribution of Pegasus Mail for the purposes of sending bulk, unsolicited commercial e-mail is prohibited under its terms and conditions of use. In order to support this prohibition, Starting with version 2.50, Pegasus Mail for Windows incorporates measures that should make it less useful to "spammers" (senders of unsolicited commercial e-mail), and which should allow users of e-mail applications that can filter mail to deal automatically with undesired "spam" messages sent using Pegasus Mail.
Pegasus Mail now adds one of three new headers to messages it sends when more than 50 recipients are present in the message. These headers can be used as filtering triggers to delete such messages. The headers are based on the number of recipients, and are as follows:
   0-50 recipients - no added header
   50-499 recipients - "X-Distribution: Moderate"
   500-4999 recipients - "X-Distribution: Bulk"
   5000+ recipients - "X-Distribution: Mass"

These headers have an internal CRC check applied to them and cannot be changed or omitted by patching the binary. We have deferred announcing the presence of these headers until now in order to give WinPMail v2.5x a chance to propagate widely, and presumably into the hands of a large number of spammers. While spammers using older versions of WinPMail will escape the new headers, they will become progressively further and further out of date and will be unable to take advantage of the newer capabilities of the system without upgrading and thus exposing themselves to automated detection.
As an example of how these headers may be useful in reducing spam levels, we show below the steps necessary to create the Pegasus Mail filtering rules that will delete such messages. Similar actions could presumably be taken in other e-mail packages supporting automated processing of this kind.
We believe this addition to Pegasus Mail should be a significant step towards reducing the prevalence of spam, or at least towards reducing the abuse of Pegasus Mail for this purpose, yet it does not significantly impact on legitimate users of the program.
Adding Pegasus Mail filtering rules to handle the new headers:
  1. Open your "New mail filtering rules", "Rules applied when folder is opened" rule set. In WinPMail v2.5x you will find this on the "Tools" menu under "Mail filtering rules".
  2. Click the "End of list" entry to ensure the rule is added at the end of the list of rules.
  3. Click "Add Rule"
  4. Click the radio button labelled "As an expression" and make sure the radio button labelled "In message headers only" is also checked.
  5. In the "Trigger text" field, type "X-Distribution:*Bulk"
  6. Set the "Action to take" to "Delete" (or whatever else you feel is appropriate).
  7. Now repeat steps 2 to 6, but at step 5 type "X-Distribution:*Mass"

Save the rules, and you're done. These rules will automatically remove any messages generated by a copy of Pegasus Mail v2.5x containing more than 500 recipients. You could also add a rule that deleted all messages containing more than 50 recipients, but doing this may occasionally result in legitimate messages being deleted.
If you receive mail from a legitimate mailing list that could contain these headers, you can prevent the message from being deleted by adding a rule higher in the list than the spam-detection rule, that triggers on some different characteristic of the message (like the sender's address) and choose the "Exit this rule set" action, or else perhaps move the "good" message to a folder. David Harris -+- Pegasus Mail
New Zealand

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