Public Class Form1
Private tagn As String = "TAGN "
Private cset As String = "ISO-2022-JP"
Private serv As String = "imap.xxx.com"
Private port As Integer = 143
Private user As String = "user"
Private pass As String = "pass"
' (SSL無し)IMAPでメール受信(TcpClientソケット通信)サンプル
' ニフティー(imap.nifty.com)でメール受信
Private Sub Button1_Click( _
ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
' IMAPサーバーに接続
Dim client As System.Net.Sockets.TcpClient
client = New System.Net.Sockets.TcpClient
client.Connect(serv, port)
' SSL無しの実装---------------------------------------------------------------
' 通信開始(SSL無し)
Dim stream As System.Net.Sockets.NetworkStream
stream = client.GetStream()
' ----------------------------------------------------------------------------
' IMAPサーバー接続時のレスポンス受信
Dim rstr As String
rstr = StreamWriteAndRead(stream, "", cset)
If rstr.StartsWith("*") = False Then
Throw New Exception("エラー:" & rstr)
End If
' LOGIN(ログイン)の送信
rstr = StreamWriteAndRead(stream, tagn & "LOGIN " & user & " " & pass & vbCrLf, cset)
If rstr.StartsWith("*") = False Then
Throw New Exception("エラー:" & rstr)
End If
' SELECT INBOX(メールボックスを選択)の送信
rstr = StreamWriteAndRead(stream, tagn & "SELECT INBOX" & vbCrLf, cset)
If rstr.StartsWith("*") = False Then
Throw New Exception("エラー:" & rstr)
End If
' SEARCH ALL(メール番号の一覧を取得)の送信
rstr = StreamWriteAndRead(stream, tagn & "SEARCH ALL" & vbCrLf, cset)
If rstr.StartsWith("*") = False Then
Throw New Exception("エラー:" & rstr)
End If
' FETCH(メールのヘッダを取得)の送信
rstr = StreamWriteAndRead(stream, tagn & "FETCH 1:* (RFC822.HEADER)" & vbCrLf, cset)
If rstr.StartsWith("*") = False Then
Throw New Exception("エラー:" & rstr)
End If
' メールのヘッダを表示
System.Diagnostics.Debug.WriteLine(rstr)
' FETCH(メールの本文を取得)の送信
rstr = StreamWriteAndRead(stream, tagn & "FETCH 1:* (RFC822.TEXT)" & vbCrLf, cset)
If rstr.StartsWith("*") = False Then
Throw New Exception("エラー:" & rstr)
End If
' メールの本文を表示
System.Diagnostics.Debug.WriteLine(rstr)
' LOGOUT(ログアウト)の送信
rstr = StreamWriteAndRead(stream, tagn & "LOGOUT" & vbCrLf, cset)
If rstr.StartsWith("*") = False Then
Throw New Exception("エラー:" & rstr)
End If
End Sub
''' <summary>
''' メールサーバとの送受信
''' </summary>
''' <param name="stm">メールサーバ通信ストリーム</param>
''' <param name="req">リクエスト(コマンド)</param>
''' <param name="cst">文字コード</param>
''' <returns>レスポンス</returns>
''' <remarks></remarks>
Private Function StreamWriteAndRead( _
ByVal stm As Object, _
ByVal req As String, _
ByVal cst As String) As String
' メールサーバへリクエスト送信
If req <> "" Then
Dim sdat() As Byte
sdat = System.Text.Encoding.GetEncoding(cst).GetBytes(req)
stm.Write(sdat, 0, sdat.Length)
stm.Flush()
End If
' メールサーバからのレスポンス受信
Dim rstr As String = ""
Dim rdat As Byte() = New Byte() {}
Dim l As Integer
Do
ReDim rdat(1024 * 1024 - 1)
l = stm.Read(rdat, 0, rdat.Length)
If l > 0 Then
ReDim Preserve rdat(l - 1)
rstr &= _
System.Text.Encoding.GetEncoding(cst).GetString(rdat)
Else
Throw New Exception("Read Error.")
End If
Loop While (req <> "" And _
rstr.StartsWith("*") = True And _
rstr.IndexOf(vbCrLf & tagn) < 0)
' レスポンス応答
Return rstr
End Function
End Class
