7.1   Why is SpamSieve not catching my spam?

There are two basic causes of poor accuracy, setup problems and improper training:

Setup

SpamSieve itself may be working properly, but if it doesn’t have access to your incoming messages, it won’t be able to tell which ones are spam. First, check SpamSieve’s log to see if SpamSieve is analyzing your messages or if you need to adjust its preferences. If SpamSieve is not analyzing your messages, you can check its setup by following these steps:

Apple Mail, Entourage, and PowerMail Setup

The setup processes for Apple Mail, Entourage, and PowerMail involves creating a rule in the mail program. When this rule is applied to a message, SpamSieve can examine its contents and send it to the spam folder (if it’s spam). Make sure that you have a rule that looks exactly like the one in the SpamSieve manual.

To test that the rule works, select a spam message in your mail program. If you are using PowerMail, go to the Mark as Spam pane of the preferences and temporarily uncheck mark it as good at the bottom of the window. Use the Train Spam (Apple Mail or Entourage) or Mark as Spam (PowerMail) command to tell SpamSieve that it is spam. Drag this message to your inbox and select it again. Then manually apply the rule:

• In Apple Mail, choose Apply Rules from the Message menu. (This will apply all the rules so, for testing purposes, go to Mail’s Preferences window and move the SpamSieve rule to the top of the rule list.) The rule worked if the message moved to the spam folder.
• In Entourage, change the category of the message to None. Then choose Apply Rule ‣ SpamSieve - Move If Spam from the Message menu. The rule worked if the message moved to the spam folder (or, for IMAP/Exchange messages, if the category was changed to Junk).
• In PowerMail, choose Perform Filter ‣ Spam: evaluate from the Mail menu. Then choose Open Log from the SpamSieve menu. The rule worked if the last entry in the log says Predicted: Spam and shows the subject for the message that you had selected.

If the rule worked, then the problem is that another rule (above it in the list) is preventing the SpamSieve rule from being applied. Dragging the SpamSieve rule higher in the list should help, as this gives the SpamSieve rule priority. In Entourage, Mailing List Manager rules are implicitly higher than the regular rules, and they can often interfere with the regular rules, even if it looks like they wouldn’t. Try unchecking Do not apply rules to list messages in the Advanced tab of each Mailing List Manager rule, or delete the Mailing List Manager rules and re-create them as regular rules.

If the rule did not work, see below for how to fix it:

Fixing the Apple Mail Rule

• Make sure that SpamSieve’s training commands appear in Apple Mail’s Message menu. If you don’t see them there, then try re-installing SpamSieve’s Apple Mail plug-in and re-launching Apple Mail.
• Make sure that the rule’s name starts with SpamSieve.
• If SpamSieve is no longer working (but was working previously), try quitting Mail and then using the Install Apple Mail Plug-In command in the SpamSieve menu. Often, this is all you’ll need to do to get it working again.

Fixing the Entourage Rule

• Make sure that your rule is of the proper type. That is, if you have a POP account, you need a POP rule; if you have an IMAP account, you need two IMAP rules.
• Try installing fresh copies of the scripts. To do this, choose Install Entourage Scripts from the SpamSieve menu, and let it replace the existing files. Then go to Entourage’s Rules window and delete and re-create the SpamSieve rule.

Fixing the PowerMail Filter

• The filter might be configured such that it excludes most messages from spam filtering. Try editing the Spam: evaluate filter so that it has just a single condition that says Always.

• Quit PowerMail, then delete the folder:

  /Users/<username>/Library/Application Support/PowerMail
  

  and then re-launch it. (If the script files that PowerMail uses to communicate with SpamSieve may be damaged, this will fix them.)

Eudora Setup

• Make sure that you see SpamSieve’s plug-in (and no other junk/spam plug-ins) listed when you choose About Message Plug-Ins from the Eudora menu.
• Make sure that the Junk Threshold is set to 50 and Hold junk in Junk mailbox is checked in Eudora’s Junk Mail settings.
• Make sure that Run junk scoring plugins on this IMAP account is checked in Eudora’s IMAP settings (if you have an IMAP account).
• Make sure that Mail isn’t junk if the sender is in an address book in Eudora’s Junk Mail pane is not checked.

Mailsmith Setup

• Make sure that Use SpamSieve is checked in the preferences.
• If you are using Leave it in “(incoming mail)”, make sure that a deposit or transfer filter isn’t acting on the spam messages before your spam filter can.

Thunderbird Setup

• Make sure that Do not mark mail as junk if the sender is in… is not checked.
• Make sure that Trust junk mail headers set by… is not checked.

Spam Messages From Your Address

If the missed spam messages have your own e-mail address in the “From” line, make sure that you check SpamSieve’s Exclude my addresses option, and that you have used the Update Address Book “Me” Card command.

Training

SpamSieve is nearly 100% accurate, but only when properly trained. For best results, the corpus should have about 65% spam messages, as shown at the bottom of the Statistics window. You can manually train SpamSieve with more messages to improve this ratio, or let it auto-train itself with incoming messages.

The messages in the corpus should be representative of the messages that you receive. Adding more messages to the corpus generally improves accuracy, but it is not necessary to have more than a few thousand messages in the corpus (and having more than that will probably reduce accuracy). If the corpus is very large or very unbalanced, and there are so many messages in it that you cannot get it close to the 65% ratio, then you should reset the corpus and re-train SpamSieve. For more information, see this section.