Use alias database MTA option

Alias and address MTA options:  (0 or 1)
The  MTA  option controls whether or not the MTA makes use of the alias database  as a source of system aliases for local addresses. The default is 1, which means that the MTA will check the database if it exists. A value of 0 will disable this use of the alias database.

See also:
 * Alias database
 * Alias and address MTA options
 * Database MTA options