In my checkout fields I have:
If fields are left blank I get the correct error messages:
Error: Please enter a valid email address
Error: Please enter your first name
Error: Please enter your last name.
But if I just type the number 1 in each field - the success-page becomes available in(test-mode) & I'm taken to http://www.sandbox.paypal.com in (Paypal test mode). (Surely typing 1 in these fields does not make these fields valid?) I thought at least all email fields in forms etc required the symbol @