Log remote mta MTA option

Transaction logging MTA options:  (0-3)
(New in MS 8.0.2.3.) The  MTA option controls whether the remote MTA name is included in  MTA message transaction log entries as a separate field and    mapping probes that correspond to an operation involving a remote SMTP or LMTP server.

Setting bit 0/value 1 enables the generation of the remote MTA and also disables the inclusion of this information in the diagnostics field; clearing the bit disables the use of a separate field. The default is 0.

If logging is enabled, the remote MTA name will be logged just after the SMTP delivery status  (  SMTP diagnostic)  field and just before the ISC status field. In XML or JSON format (  set to 4 or 5, respectively),  the reason logging, if enabled, appears as the   attribute.

Normally the  attribute only appears in XML or JSON format logs if there is remote MTA information to log. Setting bit 2 (value 4) will cause the attribute to appear unconditionally.

Bit 1 (value 2), if set, causes remote MTA information to be included in   mapping probes.

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