I have currently the problem, that messages are supposed to arrive separated at the server.

private Encoding _encode = Encoding.Default;

public Encoding DataEncoding
{
    get
    {
        return _encode;
    }
    set
    {
        _encode = value;
    }
}

public void Send(string data)
{
    Task.Run(() =>
    {
        if (this.ConnectionState != ConnectionStatus.Connected)
        {
            this.ConnectionState = ConnectionStatus.SendFail_NotConnected;
            return;
        }

        var bytes = _encode.GetBytes(data);
        SocketError err = new SocketError();
        this._client.Client.Send(bytes, 0, bytes.Length, SocketFlags.None, out err);
        if (err != SocketError.Success)
        {
            Action doDCHost = new Action(DisconnectByHost);
            doDCHost.Invoke();
        }
    });
}

The function to call the Socket.Send Method is totaly basic.
A string that needs to be send looks like this

STX-MESSAGESTRING-ETX

However, if there are many strings to be send, the message gets fragmented.
The Server receives a message that looks like this:

STX-MESSAGESTRING-ETXSTX-MESSAGESTRING2-ETXSTX-MESSAGESTRING3-ETX

What is the best way to prevent this from happening? Sadly there is no flag that indicates that the socket is currently empty or something.