I spent some time this afternoon experimenting.  Hacked out this code that seems to work (see class code-listing below).  Note: allows uploading to specific directory on your website, downloading from a specific directory to a specific local directory, and has ability to return a list of files found in the root of any directory.  I also posted a copy of the code on my DC C# Errata.

    public class FTPClient {

        // The hostname or IP address of the FTP server
        private string _remoteHost;

        // The remote username
        private string _remoteUser;

        // Password for the remote user
        private string _remotePass;

        public FTPClient(string remoteHost, string remoteUser, string remotePassword) {
            _remoteHost = remoteHost;
            _remoteUser = remoteUser;
            _remotePass = remotePassword;
        }

        public string DirectoryListing() {
            FtpWebRequest request = (FtpWebRequest)WebRequest.Create(_remoteHost);
            request.Method = WebRequestMethods.Ftp.ListDirectory;
            request.Credentials = new NetworkCredential(_remoteUser, _remotePass);
            FtpWebResponse response = (FtpWebResponse)request.GetResponse();
            Stream responseStream = response.GetResponseStream();
            StreamReader reader = new StreamReader(responseStream);

            string result = string.Empty;

            while (!reader.EndOfStream) {
                result += reader.ReadLine() + Environment.NewLine;
            }

            reader.Close();
            response.Close();
            return result;
        }




        public string DirectoryListing(string folder) {
            FtpWebRequest request = (FtpWebRequest)WebRequest.Create(_remoteHost + folder);
            request.Method = WebRequestMethods.Ftp.ListDirectory;
            request.Credentials = new NetworkCredential(_remoteUser, _remotePass);
            FtpWebResponse response = (FtpWebResponse)request.GetResponse();
            Stream responseStream = response.GetResponseStream();
            StreamReader reader = new StreamReader(responseStream);

            string result = string.Empty; 

            while (!reader.EndOfStream) {
                result += reader.ReadLine() + Environment.NewLine;
            }

            reader.Close();
            response.Close();
            return result;
        }


        public void Download(string file, string destination) {
            FtpWebRequest request = (FtpWebRequest)WebRequest.Create(_remoteHost + file);
            request.Method = WebRequestMethods.Ftp.DownloadFile;
            request.Credentials = new NetworkCredential(_remoteUser, _remotePass);
            FtpWebResponse response = (FtpWebResponse)request.GetResponse();
            Stream responseStream = response.GetResponseStream();
            StreamReader reader = new StreamReader(responseStream);

            StreamWriter writer = new StreamWriter(destination);
            writer.Write(reader.ReadToEnd());

            writer.Close();
            reader.Close();
            response.Close();
        }



        public void UploadFile(string FullPathFilename) {
            string filename = Path.GetFileName(FullPathFilename);

            FtpWebRequest request = (FtpWebRequest)WebRequest.Create(_remoteHost + filename);
            request.Method = WebRequestMethods.Ftp.UploadFile;
            request.Credentials = new NetworkCredential(_remoteUser, _remotePass);

            StreamReader sourceStream = new StreamReader(FullPathFilename);
            byte[] fileContents = Encoding.UTF8.GetBytes(sourceStream.ReadToEnd());

            request.ContentLength = fileContents.Length;

            Stream requestStream = request.GetRequestStream();
            requestStream.Write(fileContents, 0, fileContents.Length);

            FtpWebResponse response = (FtpWebResponse)request.GetResponse();

            response.Close();
            requestStream.Close();
            sourceStream.Close();
        }



    }	

RESOLVED (see my next post).

An interesting issue has arisen in a project I'm working on:

I've created the "C:/[User]/AppData/Roaming/Kyrathaba/ExcuseManager/" subdirectory programmatically, using:

Directory.CreateDirectory()

So far, so good.

But then, using my Imap code, I try to download email attachments to the above directory, and I get an Unauthorized Access Expression.  Funny, because it just let me create the directory, but it now won't let me download anything to it.

The code referenced by the link above works, if you just create a default Windows Forms project in C#.  Must have something to do with the fact that I'm trying to write a binary file into a subdirectory of /[User]/; must be upsetting UAC or something, because I am able to write simple text files to the directory.  

Any ideas what's going on?

Figured it out: I wasn't adding a filename and extension to the end of the filename I tried to build.  DUH and DOUBLE-DUH!

Turns out there isn't a problem, except me being inattentive.

Bugs happen ^_^

If you can programmatically create a subdirectory, you can write a file there, as you'd expect.

Well, it's definitely what you'd expect - I was guessing that perhaps the IMAP library was running with more paranoid security settings or something. I should really find the time to read properly about .NET security.

Have you tried tracing the UploadFile method in the VS debugger to see if there's any particular line of code that causes a hang?

It's not a good idea doing stuff like this from your UI thread, anyway... you should either schedule the task on a background worker thread, or (better) use Async I/O. I'll refrain from saying anything about having non-ui code in a btnWhatever_Click handler

Okay, my button Click event now hands the file upload off to a backgroundWorker object running on its own thread:

        private void backgroundWorker1_DoWork(object sender, System.ComponentModel.DoWorkEventArgs e) {
            MessageBox.Show("Doing some work...");
            string username = "my_username";
            string password = "my_password";
            string host = "ftp://glensforkumc.com";
            string myLocal = Path.GetDirectoryName(Application.ExecutablePath) + "\\myTextFile.txt";
            string myRemote = host + "/httpdocs/non_church/";
            clsFTPclient client = new clsFTPclient(host + "/httpdocs/non_church/", username, password);
            client.UploadFile(Path.GetDirectoryName(Application.ExecutablePath) + "\\myTextFile.txt");

        }

        private void backgroundWorker1_RunWorkerCompleted(object sender, System.ComponentModel.RunWorkerCompletedEventArgs e) {

            MessageBox.Show("I'm done uploading");
        }

The file does get uploaded, but my RunWorkerCompleted() messageBox never pops up... remove everything except the messageBox from the _DoWork() method above, and it's msgBox (as well as RunWorkerCompleted's msgBox) both fire as expected.

I'll be scratching my head over this one for a while, but it all works as expected now; no inexplicable hanging (even when doing the upload on its own asynch thread, it had 'seemed' to be hanging, in that I got a non-responsive UI):