Osync MTA option

File format MTA options: (0 or 1)
RESTRICTED.

The  MTA option controls whether MTA message queue file creation sets the O_SYNC flag. If set to 1, the O_SYNC flag is set when creating message queue file entries on disk. The default is 0. Setting O_SYNC may provide an increase in performance on ZFS file systems, but will degrade performance considerably on UFS.

See also:
 * File format MTA options