Verified on 5.4.2.0.20150820153254_83e434d Username & Password enabled if SMTP Auth is set to Plain or Login Username & Password disabled if SMTP Auth is set to None
Since the problem described in this bug report should be resolved in a recent advisory, it has been closed with a resolution of ERRATA. For information on the advisory, and where to find the updated files, follow the link below. If the solution does not work for you, open a new bug report. https://rhn.redhat.com/errata/RHBA-2015-1744.html