Log process MTA option

Transaction logging MTA options:  (0 or 1)
The  MTA option controls whether or not the ID of the process is  saved in the    file (and the   file, if a separate connection log is used).

A value of 1 enables process ID logging. A value of 0 disables it. As of MS 6.3p1, enabling XML format (  set to 4) causes the default for   to be 1; with any other format, the default is  0, as in previous versions.

The process ID will be logged after the date and time stamps in log entries---and after the node name, if   is also enabled. In XML-compatible format ( set to 4), process ID logging, if enabled, appears is the    attribute. The process ID field itself will consist of the process ID in a hexadecimal representation followed by a period, next in the case of a multithreaded channel the thread ID followed by a period, followed  by a (per process) sequence number that uniquely identifies the logging operation as a whole. That is, in the case of a single threaded channel process-id.sequence or in the case of a multithreaded channel process-id.thread-id.sequence Note in particular that via the process id and thread id, TCP/IP channel message enqueue/dequeue (E/D) records may be correlated with SMTP connection open/close (O/C) records. The sequence number provides the ability to identify all the entries associated with the processing a a specific queue entry.

is one of the most useful MTA logging options for correlating between multiple transaction records relating to the same message, observing the timing between entries, etc.

See also:
 * Transaction logging MTA options
 * MTA transaction logging
 * log_format MTA Option
 * log_node MTA Option