I have moved the site to a hosting service (hostgator). The email problems with AWS appear to be fixed, and emails are now getting sent by the forum software. However, it appears that the emails are likely to go to the spam folder, especially if you have gmail, but likely for other email services too. You can prevent that by adding osiweb.org as a whitelisted domain, or by checking for emails in your SPAM folder, and marking them "NOT SPAM."
Dave