For your current mail.txt all that is necessary is
Var txt As String = mail
Var utf8_OK As String = txt.DefineEncoding(Encodings.ISOLatin9)_
.ConvertEncoding(Encodings.UTF8)
For your current mail.txt all that is necessary is
Var txt As String = mail
Var utf8_OK As String = txt.DefineEncoding(Encodings.ISOLatin9)_
.ConvertEncoding(Encodings.UTF8)