This email validation is currently the highest practical level. It is not 100% foolproof, but is a marked improvement over any lower form of validation. This level guarantees that the domain name of the email address is not only registered, but also that it is a live Internet host that can actually receive email. This is generally considered as the base practical level of email validation. This level of validation can be easily implemented via a developer component. Similar to #2, you must first install the component package on the server. After referencing the DLL, you might use code such as:

	set MXValidate = Server.CreateObject("CompanyABC.Emailvalidate")
	emailaddress = Request.Form("emailaddress")
	MXValidate.serveraddresses = "XXX.XXX.XXX.XXX","XXX.XXX.XXX.XXX" '(backup DNS)
	MXValidate.ValidateIt(emailaddress,resultcode)
	If resultcode = False Then
		Response.Redirect("badaddress.html")
	Else
		<continue form processing>
	End If