Code:Imports System.Text.RegularExpressions Public MustInherit Class EmailValidate Protected mvar_EmailAddress As String Protected mValidationExpression As New Regex("^([a-zA-Z0-9_\-])([a-zA-Z0-9_\-\.]*)@(\[((25[0-5]|2[0-4][0-9]|1[0-9][0-9]|[1-9][0-9]|[0-9])\.){3}|((([a-zA-Z0-9\-]+)\.)+))([a-zA-Z]{2,}|(25[0-5]|2[0-4][0-9]|1[0-9][0-9]|[1-9][0-9]|[0-9])\])$") Private Function IsValid(ByVal v As String) As Boolean If Not mValidationExpression Is Nothing Then Return mValidationExpression.IsMatch(v) Else Return True End If End Function Public Property Email() As String Get Return Me.mvar_EmailAddress End Get Set(ByVal value As String) If value.Length <> 0 Then 'If any character gets entered proceed If Me.IsValid(value) = False Then Throw New Exception("Invalid Email Address format") Else Me.mvar_EmailAddress = value End If Else Me.mvar_EmailAddress = "" End If End Set End Property End Class