This section explains the options available for each rule in SpamSieve’s blocklist and whitelist windows.
Rule Columns
The meanings of the columns are as follows:
- Date
- The date that the rule was added to the blocklist.
- Header
- The part of the message that will be matched against the rule.
- Match Style
- How the rule text will be matched against the text from the message’s header.
- Text to match
- The text that will be matched against the message’s header.
- ✓ (Enabled)
If this is checked, the rule is enabled. Disabled rules do not block any messages, but they are useful because they prevent SpamSieve from re-learning a rule that you don’t want. (See Rules and Training.)
- Hits
- The number of god or spam messages that the rule blocked, a rough measure of how effective it is.
Rule Headers
When SpamSieve checks whether a message matches a rule, it compares the part of the message named by the Header column with the contents of the rule’s Text to Match column. The following are the message parts that may be used in the Header column:
- From (address)
- The e-mail address of the message’s sender.
- From (name)
- The name of the message’s sender.
- To (any address)
- The e-mail addresses of the primary recipients of the message. SpamSieve checks each recipient separately to see whether it matches the rule.
- CC (any address)
- The e-mail addresses of the carbon copy recipients of the message. SpamSieve checks each recipient separately to see whether it matches the rule.
- Reply-To (address)
- The address that you would be sending to if you replied to the message. This is often the same as the From address, but it could also be a mailing list or an alternate address for the sender. If the message does not specify a Reply-To, then the rule will not match.
- Any Recipient
- The To and CC addresses.
- Any Address
- The From, To, CC, Reply-To, and SendTo addresses.
- List-ID
- For mailing list messages, this hidden header indicates which mailing list the message was sent to.
- List-Unsubscribe
- For mailing list messages, this hidden header indicates how to unsubscribe from the mailing list. Some mailing list messages that do not have a List-ID header do have a List-Unsubscribe header.
- Mailing-List
- For mailing list messages, this hidden header indicates which mailing list the message was sent to. Some mailing list messages that do not have a List-ID header do have a Mailing-List header.
- Received (any)
- The Received headers contain information about the servers that relayed the message on its journey from the sender to the recipient.
- Return-Path
- This header contains information about where the message originated.
- Subject
- The subject of the message.
- Body (any text part)
- The contents of the message. Some messages contain more than one text part (for instance, plain text and HTML representations of the same message). The rule matches the message if any of the text parts matches the rule’s text.
- Any Character Set
The character set often indicates the language of the message. Many spam messages are sent using Asian or Cyrillic character sets, and SpamSieve is pre-configured to block these. The IANA maintains a list of character sets.
- Any Attachment Name
- Many spam messages contain attachments whose names end with .pif or .scr. SpamSieve ships with some blocklist rules pre-configured to catch messages containing spammy attachments.
Rule Match Styles
There are several different ways in which SpamSieve can compare the text in the message’s header to the rule’s text. In all cases, capitalization does not matter; lowercase letters are considered the same as their uppercase counterparts.
- Is Equal to
- The message matches the rule if its text is exactly the same as the rule’s text. This is the fastest style of matching. If you leave the text blank, the rule will match messages that have blank values for that header—for example when there is an empty Subject header. Sometimes, messages (especially spam ones) omit headers. To match an omitted header, enter <SpamSieve-Unknown-Subject>, <SpamSieve-Unknown-From>, <SpamSieve-Unknown-FromName>, or <SpamSieve-Unknown-To> depending on the header selected.
- Contains
- The message matches the rule if the message text contains the rule text.
- Starts with
- The message matches the rule if the message text begins with the rule text.
- Ends with
- The message matches the rule if the message text ends with the rule text. This is useful for matching domain names. For example, to match messages sent from Apple, you could create an Ends with rule with text @apple.com.
- Matches Regex
This is like Contains, except that the rule text is treated as a Perl-compatible regular expression. Regular expressions are a powerful way of specifying patterns of text, for instance: e-mail addresses that contain numbers before the @ sign or subjects that are longer than 30 characters.
If the regular expression entered in the Text to Match column is invalid, SpamSieve will color it in red, and it will not match any messages.