Exception Occurred: Unable to read data from the transport connection

[sentiboy]

Hi All,
I am facing an error {"Unable to read data from the transport
connection: An existing connection was forcibly closed by the remote
host."} at the runtime when I run the following code of sending email
thru PoP3:

CODE BEHIND -- -- FrmInbox.vb

Imports System 
Imports System.Net.Sockets 
Imports System.Text 
Imports System.IO 
Public Class FrmInbox 
Inherits System.Windows.Forms.Form 
 
Dim Server As TcpClient 
Dim NetStrm As NetworkStream 
Dim RdStrm As StreamReader 
 
Private Sub CmdDownload_Click(ByVal sender As System.Object, ByVal 
e As System.EventArgs) Handles CmdDownload.Click 
 
Dim i As Integer 
Dim msg As POP3Message1.Message 
Dim msgstring As String 
Dim messages1 As Integer 
Me.Cursor = Cursors.WaitCursor 
 
messages1 = connect() 
 
If messages1 = -1 Then 
Me.Cursor = Cursors.Default 
Exit Sub 
End If 
Dim originalCaption As String = Me.Text 
For i = 1 To messages1 
Me.Text = "Downloading Message " & i.ToString & "/" & _ 
messages1.ToString 
Dim msgitem As New ListViewItem 
msgstring = GetMessage(i) 
msg = CreateFromText(msgstring) 
msgitem.Text = msg._From 
msgitem.SubItems.Add(msg._Subject) 
msgitem.SubItems.Add(msg._Date) 
ListView1.Items.Add(msgitem) 
TextBox1.AppendText(msg._Body & vbCrLf) 
Next 
Me.Text = originalCaption 
Me.Cursor = Cursors.Default 
 
End Sub 
 
Private Sub ListView1_Click(ByVal sender As System.Object, ByVal e 
As System.EventArgs) 
'Dim messages As Integer 
'Dim objPOP3 As POP3Message 
TextBox1.Text = GetMessage(ListView1.SelectedIndices(0) + 1) 
 
End Sub 
 
Private Sub ListView1_KeyUp(ByVal sender As Object, ByVal e As 
System.Windows.Forms.KeyEventArgs) Handles ListView1.KeyUp 
If e.KeyCode = Keys.Delete Then 
If DeleteMessage(ListView1.SelectedIndices(0) + 1) >= 0 
Then 
ListView1.Items(ListView1.SelectedIndices(0)).Text = 
"DELETED" 
 
ListView1.Items(ListView1.SelectedIndices(0)).SubItems.Clear() 
MsgBox("Your Email Message is Deleted", 
MsgBoxStyle.Information, "Delete Message") 
End If 
End If 
End Sub 
 
Private Sub CmdClose_Click(ByVal sender As System.Object, ByVal e 
As System.EventArgs) Handles CmdClose.Click 
Call Quit() 
ListView1.Items.Clear() 
End Sub 
 
End Class

CODE BEHIND -- -- pop3message1.vb

Imports System 
Imports System.Net.Sockets 
Imports System.Text 
Imports System.IO 
 
Module POP3Message1 
 
Dim Server As TcpClient 
Dim NetStrm As NetworkStream 
Dim RdStrm As StreamReader 
 
Public Function connect() As Integer 
Dim POP3Account As String 
POP3Account = "pop.gmail.com" 
If POP3Account.Trim = "" Then Exit Function 
Try 
Server = New TcpClient(POP3Account.Trim, 110) 
NetStrm = Server.GetStream 
RdStrm = New StreamReader(Server.GetStream) 
Catch exc As Exception 
MsgBox(exc.Message) 
 
Exit Function 
End Try 
 
Dim user As String 
user = "senti[URL="http://groups.google.co.in/groups/unlock?msg=7050285a25d99e01&hl=en&_done=/group/microsoft.public.dotnet.framework.remoting/browse_thread/thread/f8404c8830b87f89/7050285a25d99e01%3Fhl%3Den"]...[/URL]@gmail.com" 
Dim data As String = "USER " + user.Trim + vbCrLf 
Dim szData() As Byte = 
System.Text.Encoding.ASCII.GetBytes(data.ToCharArray()) 
NetStrm.Write(szData, 0, szData.Length) 
Dim POPResponse As String 
POPResponse = RdStrm.ReadLine 
If POPResponse.Substring(0, 4) = "-ERR" Then 
MsgBox("Invalid user Name") 
Return -1 
End If 
Dim password As String 
password = "MyPassword" 
data = "PASS " & password & vbCrLf 
szData = 
System.Text.Encoding.ASCII.GetBytes(data.ToCharArray()) 
NetStrm.Write(szData, 0, szData.Length) 
POPResponse = RdStrm.ReadLine 
If POPResponse.Substring(0, 4) = "-ERR" Then 
MsgBox("Invalid Passwprd") 
Return (-1) 
End If 
data = "STAT" + vbCrLf 
szData = 
System.Text.Encoding.ASCII.GetBytes(data.ToCharArray()) 
NetStrm.Write(szData, 0, szData.Length) 
POPResponse = RdStrm.ReadLine 
If POPResponse.Substring(0, 4) = "-ERR" Then 
MsgBox("could not log your in") 
Return -1 
End If 
data = "Stat" + vbCrLf 
szData = 
System.Text.Encoding.ASCII.GetBytes(data.ToCharArray()) 
NetStrm.Write(szData, 0, szData.Length) 
POPResponse = RdStrm.ReadLine ' ERROR 
OCCURRED HERE 
If POPResponse.Substring(0, 4) = "-ERR" Then 
MsgBox("could not log your in") 
Return -1 
End If 
Dim parts() As String 
parts = POPResponse.Split(" ") 
Dim messages As Integer 
'Dim totsize As Integer 
'messages = parts(3) 
messages = CInt(parts(1)) 
Return messages 
 
End Function 
Public Function DeleteMessage(ByVal msgIndex As Integer) 
Dim data As String = "DELE " & msgIndex.ToString & vbCrLf 
Dim SzData() As Byte = 
System.Text.Encoding.ASCII.GetBytes(data.ToCharArray()) 
NetStrm.Write(SzData, 0, SzData.Length) 
Dim tmpString As String = RdStrm.ReadLine() 
If tmpString.Substring(0, 4) = "-ERR" Then 
MsgBox("Could Not Delete Message") 
Return (-1) 
Else 
Return 11 
End If 
End Function 
Public Sub Quit() 
Dim data As String = "Quit " & vbCrLf 
Dim szData() As Byte = 
System.Text.Encoding.ASCII.GetBytes(data.ToCharArray()) 
NetStrm.Write(szData, 0, szData.Length) 
Dim tmpString As String = RdStrm.ReadLine() 
End Sub 
Public Structure Message 
Dim _From As String 
Dim _To As String 
Dim _Date As String 
Dim _Subject As String 
Dim _CC As String 
Dim _BCC As String 
Dim _Body As String 
Dim _Received As String 
End Structure 
Public Function CreateFromText(ByVal strMessage As String) As 
Message 
Dim Mssg As New Message 
Dim brkPos As Integer 
Dim Header As String 
Dim Headers() As String 
Dim Body As String 
'Dim vField As Object 
'Dim strHeader As String 
Dim HeaderName As String 
Dim HeaderValue As String 
 
brkPos = InStr(1, strMessage, vbCrLf & vbCrLf) 
If brkPos Then 
Header = strMessage.Substring(0, brkPos - 1) 
Body = strMessage.Substring(brkPos + 1, _ 
strMessage.Length - Header.Length - 3) 
Mssg._Body = Body 
Else 
Throw New Exception("Invalid Message Format") 
Exit Function 
End If 
Headers = Split(Header, vbCrLf) 
Dim _header As String 
For Each _header In Headers 
brkPos = _header.IndexOf(":") 
If brkPos >= 0 Then 
HeaderName = _header.Substring(0, brkPos) 
Else 
HeaderName = "" 
End If 
HeaderValue = _header.Substring(brkPos + 1) 
Select Case HeaderName.ToLower 
Case "received" 
Mssg._Received = HeaderValue 
Case "from" 
Mssg._From = HeaderValue 
Case "to" 
Mssg._To = HeaderValue 
Case "cc" 
Mssg._CC = HeaderValue 
Case "bcc" 
Mssg._BCC = HeaderValue 
Case "subject" 
Mssg._Subject = HeaderValue 
Case "date" 
Mssg._Date = HeaderValue 
End Select 
Next 
Return Mssg 
End Function 
Function GetMessage(ByVal msgindex As Integer) As String 
Dim tmpString As String 
Dim Data As String 
Dim SzData() As Byte 
Dim msg As String = Nothing 
Try 
Data = "RETR " & msgindex.ToString & vbCrLf 
SzData = 
System.Text.Encoding.ASCII.GetBytes(Data.ToCharArray()) 
NetStrm.Write(SzData, 0, SzData.Length) 
tmpString = RdStrm.ReadLine() 
If tmpString.Substring(0, 4) <> "-ERR" Then 
While (tmpString <> ".") 
msg = msg & tmpString & vbCrLf 
tmpString = RdStrm.ReadLine 
End While 
End If 
Catch exc As InvalidOperationException 
MsgBox("Message Retrival Failed: " & vbCrLf & 
Err.ToString()) 
End Try 
Return msg 
End Function 
End Module

With Regards,
Sentiboy