Asp. NET read POP3 message operations

asp.net
Namespace Pop3client
{
Using System.IO;
Using System.Net;
Using System.Net.Sockets;
Please note this all code being Copyright 2002 by William J. Dean
public class Pop3client
{
public enum connect_state {disc,authorization,transaction,update};
public string User;
public string pwd;
public string Pop;
public bool error;
Public Connect_state State=connect_state.disc;

Borrowed from Agus Kurniawan's article: "Retrieve Mail from a POP3 Server Using C #" at http://www.codeproject.com/csharp/ Popapp.asp
Private TcpClient Server;
Private NetworkStream NETSTRM;
Private StreamReader RDSTRM;
private string Data;
Private byte[] szdata;
private string CRLF = "";

Public Pop3client ()
{
Nothing todo. Just create to Object
}

Public pop3client (string pop_server,string user_name,string password)
{
Put the specied server (pop_server), User (user_name) and password (password)
into the appropriate properties.
Pop=pop_server;
User=user_name;
Pwd=password;
}

#region Utility Methods, some public, some private
public string Connect (string pop_server)
{
Pop=pop_server; Put the specified server into the Pop property
return (connect ()); Call the Connect method
}
public string Connect ()
{
Initialize to the POP server. This code snipped "borrowed"
With some modifications ...
From the article ' Retrieve Mail from a POP3 Server Using C # ' at
www.codeproject.com by Agus Kurniawan
Http://www.codeproject.com/csharp/popapp.asp

Create server with Port 110
Server = new TcpClient (pop,110);

Try
{
Initialization
NETSTRM = Server.getstream ();
rdstrm= New StreamReader (Server.getstream ());

The pop session was now on the AUTHORIZATION state
State=connect_state. AUTHORIZATION;
Return (Rdstrm.readline ());
}
catch (InvalidOperationException err)
{
Return ("Error:" +err.) ToString ());
}

}
private String Disconnect ()
{
String temp= "disconnected successfully.";
if (state!=connect_state.disc)
{

Close connection
Netstrm.close ();
Rdstrm.close ();
State=connect_state.disc;
}
Else
{
Temp= "Not Connected."
}
return (temp);
}

private void Issue_command (String command)
{
Send the command to the POP server. This code snipped "borrowed"
With some modifications ...
From the article ' Retrieve Mail from a POP3 Server Using C # ' at
www.codeproject.com by Agus Kurniawan
Http://www.codeproject.com/csharp/popapp.asp
data= COMMAND + CRLF;
Szdata = System.Text.Encoding.ASCII.GetBytes (Data.tochararray ());
Netstrm.write (szdata,0,szdata.length);

}
private String Read_single_line_response ()
{
Read the response of the POP server. This code snipped "borrowed"
With some modifications ...
From the article ' Retrieve Mail from a POP3 Server Using C # ' at
www.codeproject.com by Agus Kurniawan
Http://www.codeproject.com/csharp/popapp.asp
string temp;
Try
{
temp = Rdstrm.readline ();
Was_pop_error (temp);
return (temp);
}
catch (InvalidOperationException err)
{
Return ("Error in Read_single_line_response ():" + Err. ToString ());
}

}
private String Read_multi_line_response ()
{
Read the response of the POP server. This code snipped "borrowed"
With some modifications ...
From the article ' Retrieve Mail from a POP3 Server Using C # ' at
www.codeproject.com by Agus Kurniawan
Http://www.codeproject.com/csharp/popapp.asp
String temp= "";
String sztemp;

Try
{
Sztemp = Rdstrm.readline ();
Was_pop_error (sztemp);
if (!error)
{

while (sztemp!= ".")
{
temp = SZTEMP+CRLF;
Sztemp = Rdstrm.readline ();
}
}
Else
{
Temp=sztemp;
}
return (temp);
}
catch (InvalidOperationException err)
{
Return ("Error in Read_multi_line_response ():" + Err. ToString ());
}
}
private void Was_pop_error (string response)
{
Detect if the POP server that issued the response believes that
An error has occured.

if (response. StartsWith ("-"))
{
If the character of the response is "-" then the
POP server has encountered an error executing the last
command send by the client
Error=true;
}
Else
{
Success
Error=false;
}
}
#endregion
#region POP Commands
public string DELE (int msg_number)
{
string temp;

if (state!= connect_state. TRANSACTION)
{
DELE is only valid when the POPs session was in the TRANSACTION state
temp= "Connection State not = TRANSACTION";
}
Else
{
Issue_command ("DELE" + msg_number). ToString ());
Temp=read_single_line_response ();
}
return (temp);
}

public string LIST ()
{
String temp= "";
if (state!= connect_state. TRANSACTION)
{
The pop command LIST is only valid in the TRANSACTION state
temp= "Connection State not = TRANSACTION";
}
Else
{
Issue_command ("LIST");
Temp=read_multi_line_response ();
}
return (temp);
}

public string LIST (int msg_number)
{
String temp= "";

if (state!= connect_state. TRANSACTION)
{
The pop command LIST is only valid in the TRANSACTION state
temp= "Connection State not = TRANSACTION";
}
Else
{
Issue_command ("LIST" + msg_number. ToString ());
Temp=read_single_line_response (); When the message number is supplied, expect a single line response
}
return (temp);

}

public string NOOP ()
{
string temp;
if (state!= connect_state. TRANSACTION)
{
The pop command NOOP is only valid into the TRANSACTION state
temp= "Connection State not = TRANSACTION";
}
Else
{
Issue_command ("NOOP");
Temp=read_single_line_response ();

}
return (temp);

}
public String Pass ()
{
string temp;
if (state!= connect_state. AUTHORIZATION)
{
The pop command pass are only valid in the AUTHORIZATION state
temp= "Connection State not = AUTHORIZATION";
}
Else
{
if (pwd!=null)
{
Issue_command ("pass" + pwd);
Temp=read_single_line_response ();

if (!error)
{
Transition to the Transaction state
State=connect_state. TRANSACTION;
}
}
Else
{
temp= "No Password set."
}
}
return (temp);
}
public string Pass (string password)
{
Pwd=password; Put the supplied password in the appropriate property
Return (pass ()); Call Pass () with no arguement
}

public string QUIT ()
{
QUIT is valid in all pop states

string temp;
if (state!=connect_state.disc)
{
Issue_command ("QUIT");
Temp=read_single_line_response ();
Temp + + CRLF + disconnect ();

}
Else
{
Temp= "Not Connected."
}
return (temp);

}
public string RETR (int msg)
{
String temp= "";
if (state!= connect_state. TRANSACTION)
{
The pop command RETR is only valid into the TRANSACTION state
temp= "Connection State not = TRANSACTION";
}
Else
{
Retrieve mail with number mail parameter
Issue_command ("RETR" + MSG.) ToString ());
Temp=read_multi_line_response ();
}
return (temp);

}

public string RSET ()
{
string temp;
if (state!= connect_state. TRANSACTION)
{
The pop command STAT is only valid into the TRANSACTION state
temp= "Connection State not = TRANSACTION";
}
Else
{
Issue_command ("RSET");
Temp=read_single_line_response ();
}
return (temp);

}

public string STAT ()
{
string temp;
if (state==connect_state. TRANSACTION)
{
Issue_command ("STAT");
Temp=read_single_line_response ();

return (temp);
}
Else

{
The pop command STAT is only valid into the TRANSACTION state
Return ("Connection state is not = TRANSACTION");
}
}

public string USER ()
{
string temp;
if (state!= connect_state. AUTHORIZATION)
{
The pop command USER is only valid in the AUTHORIZATION state
temp= "Connection State not = AUTHORIZATION";
}
Else
{
if (user!=null)
{
Issue_command ("user" + user);
Temp=read_single_line_response ();
}
Else
{//no user has been specified
temp= "No User specified."
}
}
return (temp);
}

public string USER (string user_name)
{
User=user_name; Put the user name in the appropriate propertity
Return (USER ()); Call USER with no arguements
}
#endregion
}

}