Log headers maxchars MTA option

New in MS 8.1.0.1, the  MTA options places a limit on the size of the header lines included in primary transaction log entries as a result of the actions of the   or    mapping. THe default is 200 bytes.

See also:
 * Transaction logging MTA options
 * MTA transaction logging
 * MTA transaction log entry format
 * log_format MTA Option
 * log_header MTA Option