Windows 2008 sp2 running Exchange 2007 sp3 rollup 2. Internal to where I work I have the Exchange server with 2 scanner/copiers and 3 unix boxes which send email thru the exchange server perfectly. Now we've acquired some additional plants with their own servers and scanners which are external to the site I work at. Thinking all I need is the ip addresses of the servers and scanners so the email will pass thru our exchanger server and out to the recipients? Just wondering if i'm correct in my thinking.

Are they sending to internal only or to external recipients? If they are just going to internal recipients, then you could just point the devices at your MX record host name, as email will be delivered correctly. If they need to send to external recipients as well then you will need to configure relaying. Options there depend on what the devices are capable of - I am not a fan of IP based relaying over the Internet, as it exposes the server. Simon.Simon Butler, Exchange MVP Blog | Exchange Resources

They would need to do both internal and external. So I would just need the ip address and on the server, they would have to relay to my exchange server. This should be able to be done.

Anything can be done, but with the Internet, doing it in a secure manner is important. The most secure manner is to use authenticated relaying, but that will require the device to support that. Simon.Simon Butler, Exchange MVP Blog | Exchange Resources