MB> What are the equivalents of mailtertable.db and access.db
MB> in qmail?

Stop asking about those chocolate-covered bananas.

<URL:http://perl.plover.com./Questions3.html>

"qmail" will act as a fallback SMTP Relay server without need for explicit
configuration in order to tell it where to send what. Just tell it the domain
names of the mailboxes for which it is to receive mail for relaying (to the
main SMTP Relay server), in exactly the way that you tell it the domain names
of the mailboxes for which it is to receive mail for local delivery.

"qmail" needs some explicit configuration to act as a _main_ SMTP Relay server
that routes mail to a _hidden_ SMTP Relay server. But that's not what you are
asking about.