We have an old-ish Minolta copier (Pitney Bowes DL 460 OS) that supports sending scans by e-mail, but doesn't have any mechanism for SMTP auth or any other kid of auth that I can see. It has a setting to type nit he mail server, and I put the IP of the Exchange box there. When I try sending, it gives a generic "SMTP error" message. The only setting on the copier other than SMTP server address is reply-to address. There, I've tried using my email@example.com as well as firstname.lastname@example.org addresses, with the same result. I think what is happeneing is probably that Exchange is rejecting the mail due to a lack of authentication.
We are running Exchange 2010 on Small Business Server 2011, and I'd like to somehow set up the particular local IP of that copier/scanner as trusted so that Exchange will always accept mail from it. Is there a way to do that?