Develop Reference

pop3 issue with trying to dowload attachments -C#

I have been looking high and low for a while to have an easy to use piece of code to have my C# project download a text file attachment on an email from gmail. I did take a look at openpop.net lib, which is the only library I see that seems promising! Can anyone show me some code that gets the job done? I looked at other peoples examples with openpop, but the api was different in their example, maybe older version? Thank you in advance for you help!

Here's how you would do this using my MailKit library which is vastly more efficient than OpenPOP.NET:
using System;
using System.Linq;
using MailKit.Net.Pop3;
using MailKit;
using MimeKit;
namespace TestClient {
class Program
{
public static void Main (string[] args)
{
using (var client = new Pop3Client ()) {
client.Connect ("pop.gmail.com", 995, true);
// Note: since we don't have an OAuth2 token, disable
// the XOAUTH2 authentication mechanism.
client.AuthenticationMechanisms.Remove ("XOAUTH2");
client.Authenticate ("joey#gmail.com", "password");
int count = client.GetMessageCount ();
int unknown = 0;
for (int i = 0; i < count; i++) {
var message = client.GetMessage (i);
foreach (var attachment in message.Attachments.OfType<TextPart> ()) {
var fileName = attachment.FileName ?? string.Format ("unknown{0}.txt", ++unknown);
// Save the content of the attachment in whatever
// charset it is in.
using (var stream = File.Create (fileName))
attachment.ContentObject.DecodeTo (stream);
}
}
client.Disconnect (true);
}
}
}
}
If you have a lot of messages in your GMail account and/or you just want to download messages with even more efficiency, GMail supports the PIPELINING extension which MailKit can take advantage of.
Instead of downloading a single message at a time, you can use GetMessages() to batch request a range of messages which will take advantage of the PIPELINING extension which vastly reduces latency and thus can greatly reduce download times.

Top level domain ignorance at using RIPE

I'm developing a simple app in c#, that can check if a domain name is available to puchase for a specific tld.
The method: I downloaded a whois-server list, I send the domain name to its whois server with a TCP client on the protocol 43, and check the servers answer.
The problem: more countries has the same whois server: "whois.ripe.net" .
If I send the full domain name(with tld), the server's answer is always "No entries found in source RIPE.". If I send the domain name without tld, I dont get any tld specific data about the status of the domain name.
The method I use:
private string GetWhoisInformation(string whoisServer, string url)
{
try
{
StringBuilder stringBuilderResult = new StringBuilder();
TcpClient tcpClinetWhois = new TcpClient(whoisServer, 43);
NetworkStream networkStreamWhois = tcpClinetWhois.GetStream();
BufferedStream bufferedStreamWhois = new BufferedStream(networkStreamWhois);
StreamWriter streamWriter = new StreamWriter(bufferedStreamWhois);
streamWriter.WriteLine(url);
streamWriter.Flush();
StreamReader streamReaderReceive = new StreamReader(bufferedStreamWhois);
while (!streamReaderReceive.EndOfStream)
stringBuilderResult.AppendLine(streamReaderReceive.ReadLine());
return stringBuilderResult.ToString();
}
catch
{
return "lekérdezés sikertelen";
}
}
Example:
I do:
GetWhoisInformation("whois.ripe.net", "pokerstars.hu")
The server's answer:
%ERROR:101: no entries found
%
% No entries found in source RIPE.
for the next command:
GetWhoisInformation("whois.ripe.net", "pokerstars")
the result contains several blocks like this:
% Information related to '80.65.254.128 - 80.65.254.159'
inetnum: 80.65.254.128 - 80.65.254.159
netname: Pokerstars
descr: Hosting
country: GB
admin-c: DC77-RIPE
tech-c: JM2352-RIPE
status: assigned PA
mnt-by: manx-telecom-mnt
changed: bill.hogg#manx-telecom.com 20101123
source: RIPE
There's no information about the domain name "pokerstars.hu". Of course, I get exactly the same answers if I want to check pokerstars.va. Pokerstars.hu is a registred domain, pokerstars.va is not.
How can I find the correct status of a domain name?

RIPE does not serve as a ccTLD whois server for any domains; like ARIN, it contains only netblock information. Each ccTLD has its own root whois server (or, that is, some of them don't have a proper whois service -- for example, the Spanish .es registry requires that you use a web client, with an obnoxious CAPTCHA you have to fill in every time).
See also http://www.ripe.net/data-tools/db although it is not very explicit about what the database does not contain.
You can get the address of the authoritative whois server by requesting the ccTLD's information from whois.iana.org.
vnix$ whois -h whois.iana.org hu | fgrep whois:
whois: whois.nic.hu
See also http://www.iana.org/domains/root/db/

I tried your code against whois.melbourneit.net and it found one of my domains no trouble. I was able to reproduce your problem running against RIPE and so I tried the same query interactively on their website - and had the same result. There's nothing wrong with your code.
tripleee is right about whois.nic.hu, I successfully used it to resolve pokerstars.hu - which leaves me wondering what the blazes is purpose of the RIPE whois server.
Thanks to triplee for showing us how to obtain the whois server friendly-name for a ccTLD.
You may find this useful:
using System;
using System.IO;
using System.Net.Sockets;
using System.Text;
namespace Whois
{
class Program
{
static void Main(string[] args)
{
string tldWhoisServer = "whois.iana.org";
string ccTldServer, query = null;
Console.Write("Query> ");
while ((query = Console.ReadLine()) != string.Empty)
{
string tld = query.Substring(query.LastIndexOf('.') + 1);
string foo = GetWhoisInformation(tldWhoisServer, tld);
foo = foo.Remove(0, foo.IndexOf("whois:") + 6).TrimStart();
ccTldServer = foo.Substring(0, foo.IndexOf('\r'));
Console.WriteLine(GetWhoisInformation(ccTldServer, query));
Console.Write("Query> ");
}
}
static string GetWhoisInformation(string whoisServer, string url)
{
try
{
StringBuilder stringBuilderResult = new StringBuilder();
TcpClient tcpClinetWhois = new TcpClient(whoisServer, 43);
NetworkStream networkStreamWhois = tcpClinetWhois.GetStream();
BufferedStream bufferedStreamWhois = new BufferedStream(networkStreamWhois);
StreamWriter streamWriter = new StreamWriter(bufferedStreamWhois);
streamWriter.WriteLine(url);
streamWriter.Flush();
StreamReader streamReaderReceive = new StreamReader(bufferedStreamWhois);
while (!streamReaderReceive.EndOfStream)
stringBuilderResult.AppendLine(streamReaderReceive.ReadLine());
return stringBuilderResult.ToString();
}
catch
{
return "Query failed";
}
}
}
}

Notify C# Client, when SMTP Server receive a new Email

I want to get all emails in my ASP.NET application that have a certain CC-recipient. To use this for future emails I didn't want to polling all the time to get them. But I can't find a way, how I can use push to get the emails instantly. Are their any frameworks in C# to help me for this?
I want to connect with my application to a mail server and register a method 'X'. Always when a new message arrived to the mail server, my application have to be notified and my application should execute the method 'X'.
I hope that this is possible with code like this:
void Application_Start()
{
...
ConnectWithTheSmtpServer();
RegisterMethodForNotification(DoSomethink);
...
}
void DoSomethink(Mail newMail)
{
// Do Somethink with the mail
}
EDIT:
I did it with the MailSystem.Net. It works very fine and is very easy to implement.
Sample Code:
void Application_Start()
{
var worker = new BackgroundWorker();
worker.DoWork += new DoWorkEventHandler(StartIdleProcess);
if (worker.IsBusy)
worker.CancelAsync();
worker.RunWorkerAsync();
}
private void StartIdleProcess(object sender, DoWorkEventArgs e)
{
if (_imap != null && _imap.IsConnected)
{
_imap.StopIdle();
_imap.Disconnect();
}
_imap = new Imap4Client();
_imap.ConnectSsl(server-name, 993);
_imap.Login(username, passwort);
var inbox = _imap.SelectMailbox("INBOX");
_imap.NewMessageReceived += new NewMessageReceivedEventHandler(NewMessageReceived);
inbox.Subscribe();
_imap.StartIdle();
}
public static void NewMessageReceived(object source, NewMessageReceivedEventArgs e)
{
// Do something with the source...
}

You are approaching this from the wrong angle.
SMTP does not support receiving mail (never mind PUSH mail). POP3 is what you can use for retrieving mail, but it does not have support for PUSH either (so you would have to pull for mail).
The IMAP4 IDLE extension is what most refer to as PUSH mail - so you will need to find a library for C# that supports IMAP4 IDLE. I found some information that will get you going in the right direction (no reason to duplicate it here):
Using C# .Net Libraries to Check for IMAP Messages
Accessing IMAP in C#
Keep in mind when choosing a solution that it needs to support IDLE.
I really like the look of MailSystem.Net as it fulfills your requirements.
Remember that your mail server also needs to have IMAP4 and IMAP4 IDLE enabled. Some mail servers don't support it, so you might be clean out of luck (and will have to use POP3 pulling).

You could send a copy of your emails(i.e. using /etc/aliases file in PostFix) to a MAIL SERVER YOU CAN HANDLE. Once there, you can implement a MAIL PROCESSOR that do whatever you want anytime a mail that MEET CERTAIN CONDITIONS arrives.
Hope that helps,

You can try this:
using System;
using System.Collections.Generic;
using System.Text;
using System.IO;
using EAGetMail; //add EAGetMail namespace
namespace receiveemail
{
class Program
{
static void Main(string[] args)
{
// Create a folder named "inbox" under current directory
// to save the email retrie enter code here ved.
string curpath = Directory.GetCurrentDirectory();
string mailbox = String.Format("{0}\\inbox", curpath);
// If the folder is not existed, create it.
if (!Directory.Exists(mailbox))
{
Directory.CreateDirectory(mailbox);
}
// Gmail IMAP4 server is "imap.gmail.com"
MailServer oServer = new MailServer("imap.gmail.com",
"gmailid#gmail.com", "yourpassword", ServerProtocol.Imap4 );
MailClient oClient = new MailClient("TryIt");
// Set SSL connection,
oServer.SSLConnection = true;
// Set 993 IMAP4 port
oServer.Port = 993;
try
{
oClient.Connect(oServer);
MailInfo[] infos = oClient.GetMailInfos();
for (int i = 0; i < infos.Length; i++)
{
MailInfo info = infos[i];
Console.WriteLine("Index: {0}; Size: {1}; UIDL: {2}",
info.Index, info.Size, info.UIDL);
// Download email from GMail IMAP4 server
Mail oMail = oClient.GetMail(info);
Console.WriteLine("From: {0}", oMail.From.ToString());
Console.WriteLine("Subject: {0}\r\n", oMail.Subject);
// Generate an email file name based on date time.
System.DateTime d = System.DateTime.Now;
System.Globalization.CultureInfo cur = new
System.Globalization.CultureInfo("en-US");
string sdate = d.ToString("yyyyMMddHHmmss", cur);
string fileName = String.Format("{0}\\{1}{2}{3}.eml",
mailbox, sdate, d.Millisecond.ToString("d3"), i);
// Save email to local disk
oMail.SaveAs(fileName, true);
// Mark email as deleted in GMail account.
oClient.Delete(info);
}
// Quit and purge emails marked as deleted from Gmail IMAP4 server.
oClient.Quit();
}
catch (Exception ep)
{
Console.WriteLine(ep.Message);
}
}
}
}

Check for unread emails

I'm looking for a way to check the number of unread emails on an email account.
Any tips?
EDIT: As described in the tags, for C#. As I learned IMAP is the way to go and I confirmed all email accounts I'm going to use have IMAP activated :)

POP
You can use OpenPOP.net to read emails using POP protocol. The problem with POP is that it does not hold details whether it was unread or not. So I think this will not be of much use to you. You have have your own way of downloading and tagging emails as read or unread.
IMAP
This question in SO has some links for examples using IMAP. IMAP has details about mail status(read/unread).
Please explain more about your requirement.

If what you want to do is get the number of unread messages in an IMAP folder, you can use MailKit to do this:
using MailKit;
using MailKit.Search;
using MailKit.Net.Imap;
...
using (var client = new ImapClient ()) {
// Note: depending on your server, you might need to connect
// on port 993 using SecureSocketOptions.SslOnConnect
client.Connect ("imap.server.com", 143, SecureSocketOptions.StartTls);
// Note: use your real username/password here...
client.Authenticate ("username", "password");
// open the Inbox folder...
client.Inbox.Open (FolderAccess.ReadOnly);
// search the folder for new messages (aka recently
// delivered messages that have not been read yet)
var uids = client.Inbox.Search (SearchQuery.New);
Console.WriteLine ("You have {0} new message(s).", uids.Count);
// ...but maybe you mean unread messages? if so, use this query
uids = client.Inbox.Search (SearchQuery.NotSeen);
Console.WriteLine ("You have {0} unread message(s).", uids.Count);
client.Disconnect (true);
}

Here is the sample of code with LumiSoft IMAP library:
using LumiSoft.Net.IMAP;
using LumiSoft.Net.IMAP.Client;
using LumiSoft.Net;
...
using (IMAP_Client client = new IMAP_Client())
{
client.Connect("imap.gmail.com", 993, true);
client.Login("your.username#gmail.com", "your_cool_password");
client.SelectFolder("INBOX");
IMAP_SequenceSet sequence = new IMAP_SequenceSet();
//sequence.Parse("*:1"); // from first to last
IMAP_Client_FetchHandler fetchHandler = new IMAP_Client_FetchHandler();
fetchHandler.NextMessage += new EventHandler(delegate(object s, EventArgs e)
{
Console.WriteLine("next message");
});
fetchHandler.Envelope += new EventHandler<EventArgs<IMAP_Envelope>>(delegate(object s, EventArgs<IMAP_Envelope> e){
IMAP_Envelope envelope = e.Value;
if (envelope.From != null && !String.IsNullOrWhiteSpace(envelope.Subject))
{
Console.WriteLine(envelope.Subject);
}
});
// the best way to find unread emails is to perform server search
int[] unseen_ids = client.Search(false, "UTF-8", "unseen");
Console.WriteLine("unseen count: " + unseen_ids.Count().ToString());
// now we need to initiate our sequence of messages to be fetched
sequence.Parse(string.Join(",", unseen_ids));
// fetch messages now
client.Fetch(false, sequence, new IMAP_Fetch_DataItem[] { new IMAP_Fetch_DataItem_Envelope() }, fetchHandler);
// uncomment this line to mark messages as read
// client.StoreMessageFlags(false, sequence, IMAP_Flags_SetType.Add, IMAP_MessageFlags.Seen);
}
Bit complicated, but works fine. Limisoft library is not perfect, so be sure you test it well.

How to send arbitrary FTP commands in C#

I have implemented the ability to upload, download, delete, etc. using the FtpWebRequest class in C#. That is fairly straight forward.
What I need to do now is support sending arbitrary FTP commands such as
quote SITE LRECL=132 RECFM=FB
or
quote SYST
Here's an example configuration straight from our app.config:
<!-- The following commands will be executed before any uploads occur -->
<extraCommands>
<command>quote SITE LRECL=132 RECFM=FB</command>
</extraCommands>
I'm still researching how to do this using FtpWebRequest. I'll probably try WebClient class next. Anyone can point me in the right direction quicker? Thanks!
UPDATE:
I've come to that same conclusion, as of .NET Framework 3.5 FtpWebRequest doesn't support anything except what's in WebRequestMethods.Ftp.*. I'll try a third party app recommended by some of the other posts. Thanks for the help!

I don't think it can be done with FtpWebRequest... The only way to specify a FTP command is through the Method property, and the documentation states :
Note that the strings defined in the WebRequestMethods.Ftp class are the only supported options for the Method property. Setting the Method property to any other value will result in an ArgumentException exception.
SITE and SYST are not among the predefined options, so I guess you're stuck...
Don't waste time to try the WebClient class, it will give you even less flexibility than FtpWebRequest.
However, there are plenty of third-party FTP implementation, open source or commercial, and I'm pretty sure some of them can handle custom commands...

The FtpWebRequest won't help you as Thomas Levesque has said in his answer. You can use some third party solutions or the following, simplified TcpClient based code which I have refactored from an answer written in Visual Basic:
public static void SendFtpCommand()
{
var serverName = "[FTP_SERVER_NAME]";
var port = 21;
var userName = "[FTP_USER_NAME]";
var password = "[FTP_PASSWORD]"
var command = "SITE CHMOD 755 [FTP_FILE_PATH]";
var tcpClient = new TcpClient();
try
{
tcpClient.Connect(serverName, port);
Flush(tcpClient);
var response = TransmitCommand(tcpClient, "user " + userName);
if (response.IndexOf("331", StringComparison.OrdinalIgnoreCase) < 0)
throw new Exception(string.Format("Error \"{0}\" while sending user name \"{1}\".", response, userName));
response = TransmitCommand(tcpClient, "pass " + password);
if (response.IndexOf("230", StringComparison.OrdinalIgnoreCase) < 0)
throw new Exception(string.Format("Error \"{0}\" while sending password.", response));
response = TransmitCommand(tcpClient, command);
if (response.IndexOf("200", StringComparison.OrdinalIgnoreCase) < 0)
throw new Exception(string.Format("Error \"{0}\" while sending command \"{1}\".", response, command));
}
finally
{
if (tcpClient.Connected)
tcpClient.Close();
}
}
private static string TransmitCommand(TcpClient tcpClient, string cmd)
{
var networkStream = tcpClient.GetStream();
if (!networkStream.CanWrite || !networkStream.CanRead)
return string.Empty;
var sendBytes = Encoding.ASCII.GetBytes(cmd + "\r\n");
networkStream.Write(sendBytes, 0, sendBytes.Length);
var streamReader = new StreamReader(networkStream);
return streamReader.ReadLine();
}
private static string Flush(TcpClient tcpClient)
{
try
{
var networkStream = tcpClient.GetStream();
if (!networkStream.CanWrite || !networkStream.CanRead)
return string.Empty;
var receiveBytes = new byte[tcpClient.ReceiveBufferSize];
networkStream.ReadTimeout = 10000;
networkStream.Read(receiveBytes, 0, tcpClient.ReceiveBufferSize);
return Encoding.ASCII.GetString(receiveBytes);
}
catch
{
// Ignore all irrelevant exceptions
}
return string.Empty;
}
You can expect the following flow while getting through the FTP:
220 (vsFTPd 2.2.2)
user [FTP_USER_NAME]
331 Please specify the password.
pass [FTP_PASSWORD]
230 Login successful.
SITE CHMOD 755 [FTP_FILE_PATH]
200 SITE CHMOD command ok.

You can try our Rebex FTP component:
// create client and connect
Ftp client = new Ftp();
client.Connect("ftp.example.org");
client.Login("username", "password");
// send SITE command
// note that QUOTE and SITE are ommited. QUOTE is command line ftp syntax only.
client.Site("LRECL=132 RECFM=FB");
// send SYST command
client.SendCommand("SYST");
FtpResponse response = client.ReadResponse();
if (response.Group != 2)
; // handle error
// disconnect
client.Disconnect();

Use sendCommand("SITE LRECL=242 BLKSIZE=0 RECFM=FB");