After much googling and struggling with trying to get request_reset_password function working. I finally came across a post that mentioned some SMTP setups require a from address. Unfortunately the documentation does not mention the 'from' field or the fact that this could be an issue, would be awesome to have this in documentation and possibly save others hours of time.
Documentation ticket over a year ago:
https://jira.appcelerator.org/browse/TIDOC-1424