Mail not working, php crash?

So i tried all of the email options because I figured I had the wrong one selected but nothing works. I checked in cpanel and my host is using sendmail, which I've used previously for contact forms outside of zen cart.

When I create an account as a fictitious user, the page goes to error when it's about to send the email, and the email never comes (though the account is created). The same thing happens when my fake user (me) tries to place an order - at checkout, the order processes it so I see it in my admin area and all, but it goes to an error and no email comes.

I've checked the error log on the server and heres what it says,

[Thu Oct 23 10:38:29 2008] [error] [client 216.254.75.202] File does not exist: /home/fiji/public_html/500.shtml, referer: http://www.fijinail.com/storefront/index.php?main_page=login
[Thu Oct 23 10:38:28 2008] [error] [client 216.254.75.202] [6641] EACCELERATOR: PHP crashed on opline 36 of popen() at /home/fiji/public_html/storefront/includes/classes/class.phpmailer.php:412, referer: http://www.fijinail.com/storefront/index.php?main_page=login

I haven't touched any of the php files so I really don't understand what's happening. Can anyone help??

Thank you!!

You may wish to check with your hosting provider on this ...

Contact Us is not doing very well on your site either and goes to a dead page on the submit ...

Yes, anything that uses email doesn't work. Even the "forgot password" links for customers and admin go to errors...

Thanks for your help.

What email method do you have set in the admin under configuration/email options be sure your host supports the method you are using which smtp auth should be the recommended method.