* STRING is the name of a file within that
* directory for this mail message.
*
- * A mail document also has two values:
+ * A mail document also has four values:
*
* TIMESTAMP: The time_t value corresponding to the message's
* Date header.
*
* MESSAGE_ID: The unique ID of the mail mess (see "id" above)
*
+ * FROM: The value of the "From" header
+ *
+ * SUBJECT: The value of the "Subject" header
+ *
* In addition, terms from the content of the message are added with
* "from", "to", "attachment", and "subject" prefixes for use by the
* user in searching. Similarly, terms from the path of the mail