isValidEmail

<%
    ' Copyright (c) 2008, reusablecode.blogspot.com; some rights reserved.
    '
    ' This work is licensed under the Creative Commons Attribution License. To view
    ' a copy of this license, visit http://creativecommons.org/licenses/by/3.0/ or
    ' send a letter to Creative Commons, 559 Nathan Abbott Way, Stanford, California
    ' 94305, USA.
 
    ' Validate an e-mail address.
    ' Supports quoted local part as well as IP address for the domain part.
    function isValidEmail(email)
        dim regEx
        dim result
 
        set regEx = new RegExp
 
        with regEx
            .IgnoreCase = True
            .Global = True
            .Pattern = "^[^@]{1,64}@[^@]{1,255}$"
        end with
 
        result = false
 
        ' Test length.
        if regEx.Test(email) then
            regEx.Pattern = "^((([\w\+\-]+)(\.[\w\+\-]+)*)|(\"[^(\\|\")]{0,62}\"))@(([a-zA-Z0-9\-]+\.)+([a-zA-Z0-9]{2,})|\[?([1]?\d{1,2}|2[0-4]{1}\d{1}|25[0-5]{1})(\.([1]?\d{1,2}|2[0-4]{1}\d{1}|25[0-5]{1})){3}\]?)$"
 
            ' Test syntax.
            if regEx.Test(email) then
                result = true
            end if
        end if
 
        isValidEmail = result
        set regEx = nothing
    end function
%>