Sorry for the trouble with your <a href="http://www.inmotionhosting.com/support/edu/website-design/using-php-and-mysql/how-to-create-a-custom-php-contact-form" target="_blank">email function</a>. I was able to make a test.php page in your public_html and verify the email function is working. I checked the <a href="http://www.inmotionhosting.com/support/edu/cpanel/cpanel-email/modfying-mx-records" target="_blank">DNS MX records</a> for your domain and its correct also. We checked your <a href="http://www.inmotionhosting.com/support/website/getting-started-guides/cpanel-logs-for-access-apache-email-error-ftp-mysql-whm" target="_blank">email logs</a> and did not find any problematic emails.
We did see you have quite a few <a href="http://www.inmotionhosting.com/support/website/website-troubleshooting/what-is-modsecurity-and-why-is-it-important" target="_blank">mod_security errors</a> within your site. Its difficult to say if the mod_security is preventing the email function from being parsed or not with the information we have. You can try <a href="http://www.inmotionhosting.com/support/website/website-troubleshooting/disable-mod-security-via-modsec-manager" target="_blank">turning mod_security off temporarily in your Mod Sec Manager in cPanel</a> to see if that remedies the problem.
We would like to look further into this; however, because this is an Open forum, you will not want to pass personal information through this medium. If you could please <a href="http://www.inmotionhosting.com/support/website/website-troubleshooting/how-to-get-great-technical-support" target="_blank">contact support</a> with the login information and steps to replicate the problem, we can check the <a href="http://www.inmotionhosting.com/support/website/server-usage/view-level-of-traffic-with-apache-access-log" target="_blank">Apache logs</a> on the fly to see if anything is causing the site to break. Sorry for the trouble.
Figured it out. I change my email address to a domain hosted in Inmotion. Before, I was using a yahoo email and it works perfectly fine. Maybe your system now implement such restrictions.