[31-Jan-2014 12:01:45] ERROR: Failed sending email to: "MYDOMAINeditedFORsecurityReasons.com" <> with subject: "Website Inquiry from DomainNameRemoved.com" (failed validation)

Have you setup your
Admin: Configuration: Email Options => so that you have valid email addresses in all the proper places?

Not saying that's the only problem but I can duplicate that error message which I copied from the /logs folder after removing the email addresses from the configuration. With all Email Options removed, the Admin:Tools:Sendmail does function but the logged error will occur when the Contact form is used.