Question

Just wondering why this is too strict, I can send very simplified emails to say [e-mail] or [e-mail]

but if I make the email any longer ([e-mail]) it does not get sent.

Instead it echos back my error message:Invalid Email Address Supplied

    // Create a function to check email 
function checkEmail($email)
{
// Add some regex 
  return preg_match('/^\S+@[\w\d.-]{2,}\.[\w]{2,6}$/iU', $email) ? TRUE : FALSE;
}

Answer 1

This part

@[\w\d.-]{2,}

is gobbling up

@gmail.com

leaving nothing for this part

[\w\d.-]{2,}

to match.

Better to reuse something already proven, see for example http://www.regular-expressions.info/email.html