Auto forward e-mail based on content

I am using Exchange 2003 Server.

A third party company automatically sends me an e-mail each time someone registers on one of my three web sites.

So, for example, I might get an e-mail that says:
   User eric@xyz-corp.com has signed up on your PRINTTOOLS web site

while another one might say:
   User rburgos@acme.com has signed up on your WEBTOOLS web site

ALL of these e-mails go to one 'catchall' e-mail address on my Exchange Server. (There is no way to direct these incoming e-mails to separate addresses, but this is what i want to figure out how to do ... or ... still let them come into a catchall account, and THEN forward them to the appropriate recipients)

So ... is there a third party program or a script that can take all of these incoming e-mails, and:
- If the word PRINTTOOLS is within the body of the e-mail, forward the e-mail to printtools@aabco.com
- If the word WEBTOOLS is within the body of the e-mail, forward the e-mail to webtools@aabco.com
- If the word DESIGNTOOLS is within the body of the e-mail, forward the e-mail to designtools@aabco.com

I tried setting up a rule in Outlook (connected directly to the Exchange server) that will do exactly what i described above, but for some reason Outlook (or Exchange) will not forward the e-mails OUTSIDE of my domain. I tried setting up the rule to forward the e-mails to someone in my domain and it works fine. But if i try to forward it to someone outside the company, it doesn't work. (I don't get any error messages)

Thank you doctors!