I have windows 2003 with bitnami stack.
When i made receive email with batch job from pop3 email server via pop3 script redmine says message NOT processed and left on the server.
I solved my problem after two days trying to debug email but with no success. Suddenly i changed "Emission email address" in Settings to be different than admin's email address.These addresses where the same and because of that mail handler didn't processed emails well. So will be good point to make check in the code if "Emission email address" is same with someone's email address in redmine . Or when entering email address in Emission email address have some type of warning message that this email address can't be same with someone' email address in redmine.

Thanks