The validation rules for standard HTML5 attributes are handled entirely by the browser using the HTML5 Constraint Validation API.As such, this plugin isn't in control of things like what qualifies as a valid email address or URL.Java Script can check the syntax of an email address to see if the address could be correct but it cannot check the address itself to see if it actually exists.This can only be done by a server-side program (e.g.If you need to support these browsers, you must add a polyfill like Ryan Seddon's H5F.
If you are intending to include a 'Contact Us' page on your Website then you will need to create a more comprehensive FORM that communicates with a CGI program located on your site's Web server.
For example, you'd be surprised at what kinds of email addresses are considered valid according to standards.
Because this plugin depends on the HTML5 Constraint Validation API, Internet Explorer 9 and older are not supported.
a CGI/Perl script on a Web server) sending a request to an Internet Mail Server, to check if the email address exists and if a connection would be accepted by the Mail Server.
However, browser-side validation can be very useful when used to filter out the more obvious mistakes in the syntax of an email address and if you are collecting email addresses for a database then browser-side validation is essential.