Marketpress Confirmtion Emails Not Sending

Sorry if this is a duplicate question; I did not see my last submission appear under "Recent Q&A Activity"...

I have recently installed Marketpress, and it appear that transaction emails are not being sent. I've confirmed that php_mail() is setup correctly, and checked that WordPress's baked in password reset function is operating properly.

Any assistance you can provide would be greatly appreciated!

-Andrew Conradi