user registration

I'm currently having troubles with a freshly installed gallery 2 with user registrations. It seems that I'm getting errors when a user tries to register. The install is just the basics nothing was modified or changed during the installation procedures. I left everything as the defaults. When I try the test email it works fine and I'm using the php's built in email function. Although for each user I'm getting the following error (Just a note I did modify the password and the admin email with *'s) :

Error (ERROR_UNKNOWN) : Could not send mail to twilliams@*********.net in modules/core/classes/helpers/MailHelper_simple.class at line 93 (GalleryCoreApi::error)
in modules/core/classes/GalleryCoreApi.class at line 2844 (MailHelper_simple::sendTemplatedEmail)
in modules/register/classes/GalleryPendingUserHelper.class at line 294 (GalleryCoreApi::sendTemplatedEmail)
in modules/register/UserSelfRegistration.inc at line 154 (GalleryPendingUserHelper::sendAdminEmail)
in main.php at line 250 (UserSelfRegistrationController::handleRequest)
in main.php at line 104
in main.php at line 88

Request variables: Array
(
[return] => /twilliams/gallery2/main.php?
[formUrl] => /twilliams/gallery2/main.php?g2_view=core.UserAdmin&g2_subView=register.UserSelfRegistration&g2_GALLERYSID=78a62763c8cabb02cdf5a2e9079e2c26
[authToken] => 0769086d1693
[controller] => register.UserSelfRegistration
[form] => Array
(
[formName] => UserSelfRegistration
[userName] => twilliams
[fullName] => Tim William
[email] =>

[password1] => *********
[password2] => *********
[CaptchaValidationPlugin] => Array
(
[word] => KUHBNP
)

[action] => Array
(
[create] => Register
)

)

[GALLERYSID] => 78a62763c8cabb02cdf5a2e9079e2c26
)

some stats....
Gallery 2.3.1
Linux
MySQL version 5.1.43
Apache version 2.2.14
PHP version 5.2.11
Firefox 3.5.7