By default, the address reversal database is used if the routability scope is set to the mail server domains. An example of a channel-specific REVERSE mapping table entry would be as follows:
REVERSE tcp_*|tcp_local|binky@macho.siroe.com $D$YRebecca.Woods@siroe.com
This entry tells the MTA that for any mail with source channel of tcp_* going out the destination channel of tcp_local to change addresses of the form binky@macho.siroe.com to Rebecca.Woods@siroe.com
To enable channel-specific reverse mapping, you must set USE_REVERSE_DATABASE option in option.dat to 13. (Default=5.)