Hex Valid Email component An Active X/COM component that checks email address syntax, domain, and username.
You can use this component with almost any Windows development tool, including ASP, VB, . Sample code Demonstrates how to validate email addresses using Hex Valid Email.
Our advanced validation checks address format (including valid characters), gets DNS (MX) records, and verifies usernames using SMTP.
Using client side Java Script is an efficient way to validate the user input in web forms.
When there are many fields in the form, the Java Script validation becomes too complex.
Validation of user input makes sense to prevent missing or malformed data, eg. Because it has attracted low-quality or spam answers that had to be removed, posting an answer now requires 10 reputation on this site (the association bonus does not count).
You cannot prevent that kind of problems by validating input.