public Letter getLetter(int number) throws IOException, ProtocolException {
Letter l;
Socket s = this.getIncommingSocket();
ReceiveProtocol protocol = this.getIncommingProtocol(s);
protocol.startSession();
protocol.authorization(info.getUsername(), info.getPassword());
l = protocol.openMessage(number);
protocol.closeSession();
s.close();
return l;
}
