Greetings again all!

I have a friend who wants to start up a business. He really would prefer RedHat (well, any linux) over windows. However he has some app that acts as a mail agent that grabs the name from the incoming mail and adds it to a db and auto-replies to it when he gets some info, but using the name in it for some personalization. Its for windows, but he was wondering about Linux. Is there anything out there that does this? He is willing to spend some cash on getting this accomplished.