XTrackHeader = X-header-name
The XTrackHeader slow.conf configuration item allows a header to be inserted into each message to show that it was already screened by slowmilt. This item defines the name part of the header (the part to the left of the colon).
The name given must not end in a colon.
XTrackHeader = X-slowmilt-reviewed
The default if this XTrackHeader item is omitted is to
not insert a header. If XTrackHeader defines a header
name, slowmilt will insert that header if it is
not already found, and give it a value that is the IP
number that was recorded:
When a later run of slowmilt finds this header,
it accepts the message without further review, because
it was already recorded once. Note that slowmilt
does not validate the record, it blindly trusts it,
after all this is mainly a mechanism to communicate
between a host and its MX servers.