In Exchange 2007, we were able to set up a receive connector with anonymous authentication that allowed internal software and hardware (printers, scanners, event notification processes) to send e-mails. It is my understanding that with Exchange 2013, creating a similar receive connector using port 25 may end up breaking Exchange. I tried to configure it to work with the default options in Exchange for port 25 but that didn't work either.
One option seems to be to use another port, but some of these simpler services will only work with port 25.
What is the best way to configure Exchange for these services to properly work?