System.Net.Mail VB.NET 3.5 System.Net.Mail.SmtpException

Question

我已經徹底搜索了網絡的解決方案，並且還沒有找到。 我試圖建立一個簡單的郵件客戶端發送文本文件作爲原始文本通過SMTP。爲此，我在VB.Net版本3.5下使用System.Net.Mail庫。

每當我嘗試發送消息時，都會收到一個System.Net.Mail.SmtpException。 我曾嘗試使用不同的郵件提供商，在不同的設置下，還沒有解決這個問題。這個問題已經在3臺獨立的計算機上測試過，所有計算機都有不同的規格 的代碼如下：

Private Sub SendEmailMessage() 
Try 
If My.Computer.Network.IsAvailable Then 
     If DataValid() Then 
       'Data is valid, send the eMail. 
       Dim MailReceiver As String = txtReceiver.Text 
       'Create the eMail Message. 
       'Dim message As New MailMessage(from:=txtMailAddress.Text, to:=MailReceiver, subject:="(MTG) <CARD> " & ID, body:="<p>" & ConstructedFileString() & "<p>") 
       Dim message As New MailMessage 
       Dim MessageFrom As New MailAddress(txtMailAddress.Text) 
       Dim MessageTo As New MailAddress(MailReceiver) 
       With message 
        .From = MessageFrom 
        .To.Add(MailReceiver) 
        .Subject = "(MTG) CARD " & ID 
        .IsBodyHtml = True 
        .Body = "<p>" & ConstructedFileString() & "<p>" 
       End With 
       'Establish eMail Client 
       Dim emailClient As New SmtpClient() 
       Dim emailCredentials As New Net.NetworkCredential 

       With emailCredentials 
        .UserName = txtMailAddress.Text 
        .Password = txtPassword.Text 
        .Domain = "gmail.com" 
       End With 

       With emailClient 
        .Host = txtHostServer.Text 
        .Port = txtPort.Text 
        .Credentials = emailCredentials 
        .EnableSsl = chkSSL.Checked 
        .Timeout = 5000 
       End With 

       'Dim MailDomain As String = "" 
       'Dim PositionAt As Byte = 0 
       'PositionAt = txtMailAddress.Text.IndexOf("@") 
       'For i = PositionAt + 1 To Len(txtMailAddress.Text) 
       ' MailDomain = MailDomain & txtMailAddress.Text.Chars(i) 
       'Next 
       'Debug.Print(MailDomain) 

       If My.Computer.Network.Ping(hostNameOrAddress:=emailClient.Host) Then 
        'Send the message. 
        emailClient.Send(message) 
       Else 
        'Could not ping, do not send. 
        ErrorOut("Could not reach the eMail Server.") 
       End If 


      Else 
       'Data is not valid, do not send the eMail. 
      End If 
    Else 
     ErrorOut("No network could be found. Check your network configurations.") 
    End If 
Catch ex As Security.SecurityException 
    'Security exception 
    ErrorOut("A Security Exception was raised.") 
Catch ex As Net.NetworkInformation.NetworkInformationException 
    'Network info exception 
    ErrorOut("Exception raised when retrieving network information.") 
Catch ex As Net.NetworkInformation.PingException 
    'Ping exception 
    ErrorOut("Exception raised when pinging the network.") 
Catch ex As Net.Mail.SmtpFailedRecipientException 
    'Recipient exception 
    ErrorOut("Mail Recipient Exception raised.") 
Catch ex As Net.Mail.SmtpException 
    'Mail Server Exception 
    ErrorOut("Mail Server Exception raised") 
Catch ex As Exception 
    'Generic Exception raised. 
    ErrorOut("General Exception raised", True) 
End Try 
End Sub 

在這個問題上的任何幫助是極大的讚賞，謝謝。

堆棧跟蹤：

System.Net.Mail.SmtpException: The operation has timed out. 
at System.Net.Mail.SmtpClient.Send(MailMessage message) 
at NetProj.EmailDialog.SendEmailMessage() in ... 

Answer 1

我相信這就是著名的SSL問題與System.Net.Mail

http://blogs.msdn.com/b/webdav_101/archive/2008/06/02/system-net-mail-with-ssl-to-authenticate-against-port-465.aspx

這是那裏的框架3.5不知道4.0，如果他們修復它或不。