Email Forwarding - but only for certain users.
OK. I've searched and searched but come up blank with what I'm trying to accomplish. Hopefully this doesn't come across as a totally dumb question...
My current setup is a MS Exchange email server with its own static IP on the Internet. I also have a SUSE 10 serving up web pages along with some PHP scripting, etc. (LAMP) with its own static IP. The Exchange server is currently my MX record in the worldwide DNS database. I have a need where a client would like to email image files to our company and then have a program access the images and file them away. I believe that I can much more easily grab and work with the images from the Linux side of things and stay away from doing any programming for the Exchange server.
So I would like to change my MX record to point at the Linux server. And then when an email comes in for a user that is doesn't recognize, forward it on to the Exchange server. If an email comes in with attached image(s) to my reception server, have it just stored on the Linux server for use by my application. This would also keep me from having to purchase another CAL for the Exchange server. Then I suppose I could also use the Linux server to do some SPAM filtering at the same time. But that would not be needed at the beginning.
Can someone either offer up suggestions of how they would go about accomplishing this? Or point me where to do my research into subjects of this nature?