Validating email address jquery
The easiest and safest way to check whether an email address is well-formed is to use PHP's filter_var() function.
According to the error message, as oned_gk say, you need a web.config key to enable the pre 4.5 validation mode.
focus Invalid focuses elements when submitting an invalid form.
Use the debug option to ease setting up validation rules, it always prevents the default submit, even when script errors occur.
Use submit Handler to implement your own form submit, eg. Use invalid Handler to react when an invalid form is submitted.
When we built our validator, we did so based on real-world data RFC spec to ensure more accurate validation.
All major mailbox providers have their own custom grammar rules that impact whether an email address is valid in the real world.