Private Sub EmailAddressCheck(email As String) As Boolean
Return Regex.IsMatch("^[a-zA-Z][\w\.-]*[a-zA-Z0-9]@[a-zA-Z0-9][\w\.-]*[a-zA-Z0-9]\.[a-zA-Z][a-zA-Z\.]*[a-zA-Z]$",email)
End Sub
If EmailAddressCheck("test@b4x.de") = True Then
Log("E-Mail is valid")
Else...