Hi charlie9,
Email issues can have a variety of causes behind them. Try reading through this article about email problems and their root causes with your server. It's for our sister plugin AWPCP, but the same plugin and steps can be used for BD as well:
http://awpcp.com/forum/faq/problems-with-email-and-awpcp/
Report back with the result of the email tracking plugin we suggest in there. If the emails are showing as sent, but you're not receiving them, the problem exists between your server and your email client. There are a number of things to check in that article which may help.