In qmail, relaying is usually controlled by the tcpserver wrapper which uses a config file at either /etc/tcp.smtp or /home/vpopmail/etc/tcp.smtp.
The config file must be compiled into a binary format – “tcp.smtp.cdb” for actual use. Here’s the command line:
tcprules /etc/tcp.smtp.cdb /etc/tcp.smtp.tmp < /etc/tcp.smtp
You don’t need to restart qmail after rebuilding the database.
