Improute forward MTA option

Alias and address MTA options:  (0 or 1)
The  MTA option controls the application of the   channel option to  forward-pointing (To:, Cc:, and Bcc: lines) addresses in the message  header. A value of 1 is the default and specifies that   should affect forward-pointing header addresses. A value of 0 disables the action of the  channel option  on forward-pointing addresses.

See also:
 * Alias and address MTA options
 * exproute_forward MTA Option
 * improute Option