我真的需要帮助一件事。我有一个网站，在那个网站上我有联系我们页面，用户可以在该页面中联系管理员关于该页面或任何其他内容。
问题是当我尝试渲染页面时，它给了我一个错误说
The SMTP server requires a secure connection or the client was not authenticated. The server response was: 5.5.1 Authentication Required. Learn more at
Description: An unhandled exception occurred during the execution of the current web request. Please review the stack trace for more information about the error and where it originated in the code.
Exception Details: System.Net.Mail.SmtpException: The SMTP server requires a secure connection or the client was not authenticated. The server response was: 5.5.1 Authentication Required. Learn more at
Source Error:
Line 21: smtp.Credentials = NetworkCred
Line 22: smtp.Port = 587
Line 23: smtp.Send(mm)
Line 24: lblMessage.Text = "Email Sent SucessFully."
Line 25: End Sub
Source File: C:\Users\user\Desktop\ContactUsForm\VB.aspx.vb Line: 23
我真的不知道该怎么办。我的 VB 背后的代码是：
Imports System.Net
Imports System.Net.Mail
Partial Class VB
Inherits System.Web.UI.Page
Protected Sub btnSend_Click(ByVal sender As Object, ByVal e As EventArgs)
Dim mm As New MailMessage("sender@gmail.com", "reveiver@gmail.com")
mm.Subject = txtSubject.Text
mm.Body = "Name: " & txtName.Text & "<br /><br />Email: " & txtEmail.Text & "<br />" & txtBody.Text
If FileUpload1.HasFile Then
Dim FileName As String = System.IO.Path.GetFileName(FileUpload1.PostedFile.FileName)
mm.Attachments.Add(New Attachment(FileUpload1.PostedFile.InputStream, FileName))
End If
mm.IsBodyHtml = True
Dim smtp As New SmtpClient()
smtp.Host = "smtp.gmail.com"
smtp.EnableSsl = True
Dim NetworkCred As New System.Net.NetworkCredential()
NetworkCred.UserName = "sender@gmail.com"
NetworkCred.Password = "senderpassword"
smtp.UseDefaultCredentials = True
smtp.Credentials = NetworkCred
smtp.Port = 587
smtp.Send(mm)
lblMessage.Text = "Email Sent SucessFully."
End Sub
End Class
错误在第 23 行，它说 smtp.Send(mm)
我真的很需要。请任何人都可以帮助我。