SpamfilterN includeheaders MTA options

Spamfilter MTA options:    (0 or 1)
(New in 7.0.5) Each    MTA option specifies  whether or not any header lines added to a message due to a   flag in either a   mapping table or a  recipient address    mapping table will be passed  over to the respective  th spam/virus filter package as part of the regular message header. A value of 1 causes such header lines to be passed over; a value of 0, the default, disables this capability.

See also:
 * Spamfilter MTA options
 * FROM_ACCESS mapping table
 * Recipient access mapping tables