Log filename MTA option

Transaction logging MTA options:  (0-7)
The  MTA option controls whether or not the names of the files in which messages are stored are saved in the   file or included in    mapping probes. Setting bit 0 (value 1) enables file name logging. When file name logging is enabled, the file name will appear as the first field after the final form envelope To: address. In XML or JSON format ( set to 4 or 5, respectively), file name logging, if enabled, appears as the   attribute. As of MS 6.3p1, enabling XML or JSON format ( set to 4 or 5) causes the default for   to be 1 (filename logging enabled); with any other format, the default is 0 (file name logging disabled), as in earlier versions. New in 7.0-3.01, bit 1 (value 2), if set, causes filename information to be included in  mapping probes.

Normally the  attribute only appears in XML or JSON format logs if there is filename information to log. As of MS 8.0.2.3, setting bit 2 (value 4) will cause the attribute to appear unconditionally.

See also:
 * Transaction logging MTA options
 * MTA transaction logging
 * Triggering effects from transaction logging with LOG_ACTION
 * log_format MTA Option