尝试通过 .NET 功能发送电子邮件

Question

所以，我正在尝试使用以下代码发送电子邮件，但收到此错误：

System.Net.Mail.SmtpException: The SMTP server requires a secure connection or the client was not authenticated. 

我已经允许不安全的应用程序向我发送电子邮件，并在gmail上关闭了两步验证，当然，我Net.NetworkCredential("[e-mail]", "mypassword")替换为我的真实电子邮件和密码，但我仍然收到该错误。
我正在通过调试运行程序VB但这并不重要。

Private Sub SendBtn_Click(ByVal sender As System.Object, _
ByVal e As System.EventArgs) Handles SendBtn.Click
    Try
        Dim SmtpServer As New SmtpClient()
        Dim mail As New MailMessage()
        SmtpServer.UseDefaultCredentials = False
        SmtpServer.Credentials = New  _
    Net.NetworkCredential("[e-mail]", "mypassword")
        SmtpServer.Port = 587
        SmtpServer.Host = "smtp.gmail.com"
        mail = New MailMessage()
        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"
        mail.Priority = MailPriority.High
        SmtpServer.Send(mail)
        MsgBox("mail send")
    Catch ex As Exception
        MsgBox(ex.ToString)
    End Try
End Sub    

Answer 1

异常表明SMTP服务器需要安全连接。尝试启用 SSL

SmtpServer.EnableSsl = true;

Answer 2

"客户端未通过身份验证"只是一个想法：您是否使用Google双因素授权？