This is a follow-up to the redir posting I made a while ago.
I had to install it on a CentOS 6.2 system. Redhat (and CentOS) are now using upstart instead of the old System V inittab to control jobs. Without getting into the reasons, while it gives greater flexibility, it is also more complicated.
To make redir start automatically, and to restart if it stops, I created the following small Upstart script. To use it, just put it into a file: /etc/init/redir.conf, and run the command below to tell init to reload the configuration files. Be sure to replace the localIPaddress and smtp.<server> with your appropriate values. This script assumes that redir is in /usr/local/sbin, replace it with wherever you put the program.
description "SMTP redirection using redir"
start on started stop on shutdown
script exec /usr/local/sbin/redir --lport=587 --laddr=<localIPaddress> --caddr=smtp.<server> --cport=25 end script
/sbin/initctl start redir