邮件发送失败。无法连接到远程服务器。套接字操作

Question

所以我试图通过 VB.net 代码发送电子邮件，但我一直收到此错误。我已经禁用了我的防火墙，当它没有从文本框中获取文本时，我可以成功发送电子邮件。我知道我有正确的设置，因为当我发送一封正文为 1 行的电子邮件时它会起作用。

Private Sub SendMessage(ByVal SmtpHost As String, ByVal SmtpPort As Integer, ByVal ssl As Boolean, ByVal SmtpUsername As String, ByVal SmtpPassword As String, ByVal mail_from As String, ByVal display_name As String, ByVal Send_To As String, ByVal subject As String, ByVal Body As String, Optional ByVal Attachments As String() = Nothing)
        Using smtp As New SmtpClient
            smtp.Host = SmtpHost
            smtp.Port = SmtpPort
            smtp.UseDefaultCredentials = False
            smtp.Credentials = New Net.NetworkCredential(SmtpUsername, SmtpPassword)
            smtp.EnableSsl = ssl

            Dim message As New MailMessage()
            Try
                message.From = New MailAddress(mail_from, display_name, System.Text.Encoding.UTF8)
                message.To.Add(Send_To)
                message.Subject = subject
                message.Body = Body
                If Attachments IsNot Nothing Then
                    For Each attachment As String In Attachments
                        message.Attachments.Add(New Attachment(attachment))
                    Next
                End If
                message.ReplyToList.Add(New MailAddress(mail_from))

                smtp.Send(message)
            Catch ex As Exception
                Debug.WriteLine(ex)
            End Try
        End Using

错误：

System.Net.Mail.SmtpException: Failure sending mail. ---> System.Net.WebException: Unable to connect to the remote server ---> System.Net.Sockets.SocketException: A socket operation was attempted to an unreachable network 0.0.0.1:465
   at System.Net.Sockets.Socket.DoConnect(EndPoint endPointSnapshot, SocketAddress socketAddress)
   at System.Net.ServicePoint.ConnectSocketInternal(Boolean connectFailure, Socket s4, Socket s6, Socket& socket, IPAddress& address, ConnectSocketState state, IAsyncResult asyncResult, Exception& exception)
   --- End of inner exception stack trace ---
   at System.Net.ServicePoint.GetConnection(PooledStream PooledStream, Object owner, Boolean async, IPAddress& address, Socket& abortSocket, Socket& abortSocket6)
   at System.Net.PooledStream.Activate(Object owningObject, Boolean async, GeneralAsyncDelegate asyncCallback)
   at System.Net.ConnectionPool.GetConnection(Object owningObject, GeneralAsyncDelegate asyncCallback, Int32 creationTimeout)
   at System.Net.Mail.SmtpConnection.GetConnection(ServicePoint servicePoint)
   at System.Net.Mail.SmtpClient.Send(MailMessage message)
   --- End of inner exception stack trace ---
   at System.Net.Mail.SmtpClient.Send(MailMessage message)
   at EmailSender.Form1.Timer2_Tick(Object sender, EventArgs e)

Answer 1

您的代码可能没有任何错误。但是，如果您的邮件帐户配置不正确，则会出现此特定 'Failure Sending Mail'。您必须允许访问第三方或外部应用程序才能使用邮件的 SMTP 服务。您可以在邮件设置中更改它。

改变它并尝试。这可能有用。

Answer 2

Try
Dim mMailMessage As MailMessage = New System.Net.Mail.MailMessage()
Dim fromEmail As String = "<sender_mail_ID"
Dim fromPW As String = "<sender_password>"
Dim toEmail As String = "<Receiver_mail_ID>"
mMailMessage.From = New MailAddress(fromEmail)
mMailMessage.[To].Add(toEmail)
mMailMessage.Subject = "<Subject goes here>"
mMailMessage.Body = "<Message AKA Body goes here>"
mMailMessage.DeliveryNotificationOptions = DeliveryNotificationOptions.OnFailure

Dim smtpClient As New SmtpClient("smtp.gmail.com", 587)
smtpClient.EnableSsl = True
smtpClient.DeliveryMethod = SmtpDeliveryMethod.Network
smtpClient.UseDefaultCredentials = False
smtpClient.Credentials = New NetworkCredential(fromEmail, fromPW)

smtpClient.Send(mMailMessage.From.ToString(), mMailMessage.[To].ToString(), mMailMessage.Subject, mMailMessage.Body)

Catch ex As Exception

End Try

别忘了使用：

Imports System.Net.Mail
Imports System.Net

Answer 3

我的 2 美分。在我的例子中，我把所有的东西都布置得很完美，但让我失望的是，我没有意识到我在后台有 privateinternetaccess 应用程序运行，它阻止了每一次连接到服务器的尝试。不酷:(

邮件发送失败。无法连接到远程服务器。套接字操作

Failure Sending Mail. Unable to connect to remote server. A socket operation

vb.net

gmail

smtp

visual-studio-2012