Max internal blocks MTA option

File format MTA options:  (integer)
The  MTA option specifies how large (in MTA blocks---see the    MTA option) an  incoming message the MTA will buffer entirely in memory; messages larger than this size will be written to temporary files (in the area specified by the    MTA option -- or the   MTA Tailor file option, in  legacy configuration). (Prior to MS 6.0, the area such files were written to was controlled by the now obsolete  MTA Tailor file option.)  The default is 30.

For systems with lots of memory, increasing this value may provide a performance improvement.

Note that  does not affect incoming LMTP messages; that is, it does not affect the  LMTP server&#x27;s handling of incoming messages. As of circa 6.2p5/6.3, the LMTP server will buffer in memory up to a default of 1,000,000 bytes  (in MS 6.2p5 this number is hard-coded and not configurable) or the value set for the LMTP server   TCP/IP-channel-specific option of an incoming message, and after that will buffer to a temporary file (in the    or    directory). Prior to this change, the LMTP server did not do in-memory buffering and instead always buffered to temporary files (in ).

See also:
 * File format MTA options
 * block_size MTA Option
 * tmpdir Option
 * imta_tmp MTA Option
 * error_text_temporary_write_error MTA Option
 * BUFFER_SIZE TCPIP-channel-specific option
 * LMTP back end TCPIP channel
 * MTA performance tuning