I recently got a new dedicated private server from 1&1. It has the latest version of Plesk Panel (11.5.30). On all of my webpages hosted from the server, none of them can send emails. Whenever I test this from here http://championsfunding.com/contact-us, it says that it successfully sent the email but I receive no emails at all. Here's a test PHP mail script with more detailed information: http://championsfunding.com/mail_test.php. Any help would be appreciated.

Update 5/7/14:

I skimmed through the mail log and found no problems except

May 7 10:05:53 u17259487 qmail: 1399471553.284374 delivery 29: deferral: ./Maildir:_No_such_file_or_directory/
I created the Maildir folder in the root folder and still no emails.

Here's the log maillog.txt