not receiving WP emails (notification, contact form, etc)

apparently, i am unable to receive emails via my wordpress site. i was not made aware until i tried to add a “contact form” plugin (this one: http://ideasilo.wordpress.com/2007/04/30/contact-form-7/)

i did not receive any of the email through the plugin. to test, i was asked if i received emails for new registered members, or comments, and neither of those sent emails, as well.

i think i have everything set properly in “Discussion Settings” (everything is checked except “An administrator must always approve the comment “) and i am able to receive all other types of email to that address, rob@toonbarn.com

anything else you can suggest to fix the issue?