This regular expression will not verify if the particular email id exists or not. Instead, this regex is to validate the format of email id In jquery var ValidateEmail= function (email) { var regexp = new RegExp('^[^\s@]+@[^\s@]+\.[^\s@]+$'); var check = $(email).val(); if (!regexp.test(check)) { alert('Invalid e-mail!Please enter the e-mail ID in correct format'); $('#EmailID').css('border-color', 'red');... Continue Reading →