Log header MTA option

Transaction logging MTA options:  (0, 1, 2)
The  MTA option controls whether the MTA writes message headers to the  message transaction log file,. Or, as of MS 6.0, see also the channel option , which may be used to enable this facility on a  per-channel basis, as well as to override   on a per-channel basis.

Originally, the permitted values for  were merely 0 or 1. As of at least MS 6.1, the option takes a bit-encoded integer value instead, with the lowest two bits defined as a group. A value of 1 for these bits enables message header logging for both enqueue and dequeue directions; a value of 2 enables message header logging for message enqueues, without enabling logging for message dequeues. A value of 0, the default, disables message header logging. As of MS 8.0.2, a value of 3 for the lowest two bits is also supported, which enables header logging during dequeues but not enqueues.

As of MS 8.1.0.1, bit 2, value 4, is also defined. If set it causes header logging to be included in the transaction log entry itself. A value of 0 logs header information in separate records.

Note that only outermost message headers are available for logging purposes; the "inner" headers on inner MIME parts, if any, are not available. The specific headers written to the log file are controlled by a site-supplied  file in legacy configuration or unified configuration prior to MS 8.1.0.1. As of MS 8.1.0.1, the  MTA option should be used to control which headers are written. The format of this file/option is that of other MTA header option files. For instance, a  file containing To: MAXIMUM=1 From: MAXIMUM=1 Defaults: MAXIMUM=-1 would result in writing the first To: and the first From: header per message to the log file.

When header field logging is enabled and  is 1, 2, or 3, the header fields are logged in the format: dd-mmm-yyyy hh:mm:ss.ss &#x3e; header-line or up to two additional fields may be present (if   is 1 and   is 1 -- the header line  logging makes no display of any other fields): dd-mmm-yyyy hh:mm:ss.ss node process-field &#x3e; header-line with one such line per header line to be logged. In XML-compatible format ( set to 4), the  header fields are   elements.

When enabling, consider also enabling  , as it is helpful for correlating header entries with corresponding regular message entries.

If the goal is to record subsets of information from one or more header lines, rather than necessarily logging full header lines, see as an alternative to  the (both new-in-MS-8.0)   MTA option and Sieve " " action.

See also:
 * Transaction logging MTA options
 * MTA transaction logging
 * MTA transaction log entry format
 * log_format MTA Option
 * logheader Option
 * log_process MTA Option
 * log_node MTA Option
 * log_transactionlog MTA Option