VB.NET: Text encoding

[flyspekc]

Hi everyone!

I'm facing a problem that I can not solve.
I'm developping a VB.NET application to read my mail.
However, some of my mail messages are encoded in ISO-8859-1.

How can I convert my stream to ISO-8859-1?

Here's my (not working) code:

Shared Function ReadMessage(ByVal sslStream As SslStream) As String
        Dim buffer(2048) As Byte
        Dim messageData As StringBuilder = New StringBuilder
        Dim bytes As Integer = -1
 
        bytes = sslStream.Read(buffer, 0, buffer.Length)
 
        Dim decoder As Decoder = Encoding.GetEncoding("iso-8859-1").GetDecoder
        Dim chars(decoder.GetCharCount(buffer, 0, bytes, True)) As Char
 
        decoder.GetChars(buffer, 0, bytes, chars, 0, True)
        messageData.Append(chars)
 
        Return messageData.ToString
End Function

What I'm doing wrong?

Thanks in advance,
Pedro