Options hash size MTA option

Internal size MTA options:  (1-1000000)
The  MTA option sets the internal hash size for MTA options (Unified Configuration   options or legacy configuration   options). The default is 512; the maximum is 1,000,000. Attempts to set this option to more than its maximum 1,000,000 will result in an mm_init error, "OPTIONS_HASH_SIZE exceeds maximum".

See also:
 * Internal size MTA options