Postfix: Rewrite address

Hello,

I have an OS X server running 10.8.5. I have a couple of cron jobs setup that I want to receive e-mail for when they run, but my e-mail server rejects the e-mails because they don't come from an FQDN. The e-mails come from <root@ecserver.local>, but I want to re-write the address to <root@clientdomain.com>.

I do this all the time on Linux server: First, I add the following to '/etc/postfix/main.cf':

sender_canonical_maps = hash:/etc/postfix/canonical

I create (or edit) a file called '/etc/postfix/canonical' and make the following entry:

root@ecserver.local root@clientdomain.com

I then run 'postmap /etc/postfix/canonical' and then 'postfix restart'.

In this particular case I have done all the above and also run 'launchctl unload /System/Library/LaunchDaemons/org.postfix.master.plist' followed by 'launchctl load /System/Library/LaunchDaemons/org.postfix.master.plist'

Is there a different way to do this on OS X?

Thanks! :-)