Counters MTA options

The MTA has a number of options relating to its counters.

The   MTA option relates to MTA circuit check counter binning. The   and    MTA options relate to MTA counters binning.

See also:
 * circuitcheck_completed_bins MTA Option
 * enable_delay_timers MTA Option
 * log_debug MTA Option
 * log_delay_bins MTA Option
 * log_frustration_limit MTA Option
 * log_size_bins MTA Option
 * log_sndopr MTA Option
 * log_statistics MTA Option
 * sndopr_prefix MTA Option
 * sndopr_priority MTA Option
 * MTA options