What headers are added to emails that are scanned by SpamAssassin™ ?
All email messages scanned by SpamAssassin™ have these headers set:
X-Spam-Score: When trying to identify spam, SpamAssassin(tm) assigns a numeric score to each message. This score is listed in the X-Spam-Score: header for each message. For example: X-Spam-Score: 6.3
X-Spam-Checker-Version: The X-Spam-Checker-Version: header lists the version of SpamAssassin(tm) and the name of the server that was used to scan the message. This info is useful for system administrators, and can be ignored by end users.
X-Spam-Level: When trying to identify spam, SpamAssassin(tm) assigns a numeric score to each message. This numeric score is converted to a number of asterisks equal to the score of the message (rounded down), and added to the X-Spam-Level header. For example, a spam score of 3.6 would generate the following header: X-Spam-Level: ***
X-Spam-Status: The X-Spam-Status: is added to all messages and includes summary information including spam status (yes/no), score, what tests were triggered, and the SpamAssassin version. Here is an example:
X-Spam-Status: Yes, hits=6.2 required=5.0 tests=REVERSE_AGING,VIAGRA
autolearn=no version=2.64-servername_config_v2
In addition, email messages identified as spam also have these headers set:
X-Spam-Flag: This header is added if SpamAssassin(tm) identifies the message as being spam: 'X-Spam-Flag: YES'. You can use this message to filter spam in applications such as Outlook, Eudora, Thunderbird, etc.
X-Spam-Report: When SpamAssassin(tm) scans a message it applies a series of "tests" to the message. Each test has a score. If the cumulative score for a message is over a specefied number (5 is the default) then the message is identified as spam. When a message is identifed as being spam, SpamAssassin(tm) adds the X-Spam-Report header to the message. This header lists all of the tests that matched, and their corresponding scores. See http://www.spamassassin.org/tests.html for a list of tests (and their corresponding scores) that SpamAssassin(tm) uses. Here is an example X-Spam-Report header:
X-Spam-Report:
* 0.3 RCVD_NUMERIC_HELO Received: contains a numeric HELO
* 4.3 REVERSE_AGING BODY: Reverses Aging
* 1.9 VIAGRA BODY: Plugs Viagra
