Article ID: 3159, created on Nov 30, 2007, last review on Oct 6, 2015
If you use qmail + vpopmail, the following commands should be enough:
# echo "192.168.1.1:allow,RELAYCLIENT=\"\"" > > ~vpopmail/etc/tcp.smtp
# tcprules ~vpopmail/etc/tcp.smtp.cdb tcp.smtp.tmp < ~vpopmail/etc/tcp.smtp
# chown vpopmail ~vpopmail/etc/*
Make sure to insert your IP address instead of the 192.168.1.1 and add a full path to the tcprules program if it isn't in the system paths.