使用 Gmail 发送电子邮件会出现超时错误 [英] Sending email using Gmail gives a time out error

问题描述

我们正在测试一些代码以使用 Gmail 从表单发送电子邮件，但出现超时错误.

We are testing some code to send email messages using Gmail from a form, but get a time out error.

您能告诉我们此代码中缺少什么来发送电子邮件吗?

Can you tell us what is missing from this code to get the email message sent?

    Try
        Dim SmtpServer As New SmtpClient()
        Dim mail As New MailMessage()

        SmtpServer.EnableSsl = True
        SmtpServer.Credentials = New Net.NetworkCredential("[e-mail]", "MyPasswordGoesHere")
        SmtpServer.Port = 465
        SmtpServer.Host = "smtp.gmail.com"

        mail.From = New MailAddress("[e-mail]")
        mail.To.Add("[e-mail]")
        mail.Subject = "Test Mail"
        mail.Body = "This is for testing SMTP mail from GMAIL"

        SmtpServer.Send(mail)

        MsgBox("mail sent")

    Catch ex As Exception
        MsgBox(ex.ToString)
    End Try

更新:使用 MailBee 更改代码.这就是我们向所有客户发送电子邮件的方式:

Update: Code change using MailBee. This is how we are doing emails to all the customers:

    Dim strSqlStatement As String = "Select CustomerName, Email " & _
                               "From Customers " & _
                              "Where Email Is Not Null"
    If IsConnected() Then

        ' Set up the sql command and lookup the parent.
        '----------------------------------------------
        Using objSqlCommand As SqlCommand = New SqlCommand(strSqlStatement, ObjConnection)

            With objSqlCommand

                ' Open the SqlConnection before executing the query.
                '---------------------------------------------------
                Cursor = Cursors.WaitCursor

                ObjConnection.Open()

                Dim objDataReader As SqlDataReader = .ExecuteReader()

                ' Go through all the customers and send out the promotion emails.
                '----------------------------------------------------------------
                If objDataReader.HasRows Then

                    MailBee.Global.LicenseKey = "My license key goes here."

                    Dim objSMTP As New Smtp
                    Dim server As New SmtpServer(TextBoxSMTPServer.Text, TextBoxUserName.Text, TextBoxPassword.Text)

                    'SmtpServer.Host = TextBoxSMTPServer.Text
                    'SmtpServer.Port = TextBoxPort.Text
                    'SmtpServer.Timeout = 100

                    'If TextBoxUseSSL.Text = "Yes" Then
                    '    SmtpServer.EnableSsl = True
                    'Else
                    '    SmtpServer.EnableSsl = False
                    'End If

                    'If TextBoxUseDefaultCredentials.Text = "Yes" Then
                    '    SmtpServer.UseDefaultCredentials = True
                    'Else
                    '    SmtpServer.UseDefaultCredentials = False
                    'End If

                    'SmtpServer.Credentials = New Net.NetworkCredential(TextBoxUserName.Text, TextBoxPassword.Text)


                    objSMTP.SmtpServers.Clear()
                    objSMTP.SmtpServers.Add(server)

                    While objDataReader.Read()
                        If objDataReader("Email").ToString <> "" Then

                            objSMTP.Message.From.AsString = TextBoxEmailFrom.Text
                            objSMTP.Message.To.AsString = objDataReader("Email").ToString
                            objSMTP.Message.Subject = "Promotion: " & TextBoxID.Text
                            objSMTP.Message.BodyPlainText = "Dear " & objDataReader("CustomerName") & "," & vbCrLf & vbCrLf & TextBoxPromotionBodyText.Text

                            Try
                                objSMTP.Send()

                            Catch exBadPassword As MailBeeSmtpLoginBadCredentialsException
                                MsgBox("The login name or password is not correct.", MsgBoxStyle.Exclamation, "Email")
                                blnThereWereErrors = True

                            Catch exBadFromAddress As MailBeeSmtpRefusedSenderException
                                MsgBox("The sender email must be the same as the user's email address.", MsgBoxStyle.Exclamation, "Email")
                                blnThereWereErrors = True

                            Catch ex As Exception
                                MsgBox(ex.Message)
                                blnThereWereErrors = True
                            End Try
                        End If

                        If blnThereWereErrors Then
                            Exit While
                        End If
                    End While

                    If blnThereWereErrors = False Then
                        MessageBox.Show("Mass emailing has completed." & vbCrLf, _
                                "Email Message.", _
                                MessageBoxButtons.OK, _
                                MessageBoxIcon.Information)
                    End If
                End If

                objDataReader.Close()
                ObjConnection.Close()

                Cursor = Cursors.Default
            End With ' objSqlCommand
        End Using ' objSqlCommand

推荐答案

尝试使用不同的端口号.您不能将端口 465 与 System.Net.Mail 一起使用，因为它只支持显式 SSL".查看此页面了解更多信息.

Try using a different port number. You cannot use port 465 with System.Net.Mail as it only supports "Explicit SSL". Have a look at this page for more info on this.

通过 VB.NET 发送邮件时，Gmail 将接受端口 25 或 587，但使用端口 465 会超时.

Gmail will accept port 25 or 587 when sending mail via VB.NET but times out using port 465.

还要确保你有 UseDefaultCredentials = False

还请查看 此示例，了解如何使用C# 中的 GMail 可能会为您提供更多线索.

Also have a look at this example on how to send mail using GMail in C# it might give you some more clue.

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