Imports System

Imports System.Text.RegularExpressions

Public Module Module1

    Public Sub Main()

        Dim email = "EAC-1@DEV.REDTECHNOLOGY.COM"

        Dim emailRegex1 As Regex = New Regex("^[a-z0-9!#$%&'*+/=?^_`{|}~-]+(?:\.[a-z0-9!#$%&'*+/=?^_`{|}~-]+)*@(?:[a-z0-9](?:[a-z0-9-]*[a-z0-9])?\.)+[a-z0-9](?:[a-z0-9-]*[a-z0-9])?$" ) ', RegexOptions.IgnoreCase)

        Dim match1 As Match = emailRegex1.Match(email)

        Console.WriteLine("Email is")

        Console.WriteLine(email)

        Console.WriteLine("current regex result is")

        If match1.Success Then

            Console.WriteLine("success")

        else

            Console.WriteLine("failed")

        End If      

​

        Console.WriteLine()

        email = email.toLower()

        match1 = emailRegex1.Match(email)

        Console.WriteLine("Email is")

        Console.WriteLine(email)

        Console.WriteLine("current regex result is")

        If match1.Success Then

            Console.WriteLine("success")

        else

            Console.WriteLine("failed")

        End If      

    End Sub

End Module