信箱不可用.服务器响应是:访问被拒绝 - 无效HELO名称(请参阅RFC2821 4.1.1.1)

Question

我正在运行Windows Server 2008 R2，但是正在获得SMTP邮件例外：

邮箱不可用。服务器响应是：访问被拒绝 - 无效的HELO名称（请参阅RFC2821 4.1.1.1）

codebehind：

Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load
    Dim NewMail As New System.Net.Mail.MailMessage
    Dim str1 As String = String.Empty
    str1 = Convert.ToString(System.Configuration.ConfigurationManager.AppSettings("SmtpEmail")) '[e-mail]
    Dim fromaddress As MailAddress = New MailAddress(str1)
    NewMail.From = fromaddress
    NewMail.Sender = fromaddress
    NewMail.IsBodyHtml = True
    NewMail.Subject = "TEST"
    NewMail.Body = "This is Testing..."
    NewMail.Priority = System.Net.Mail.MailPriority.Normal
    NewMail.To.Add("[e-mail]")
    Dim SmtpMail As New SmtpClient()
    SmtpMail.Port = 25
    SmtpMail.Host = ConfigurationManager.AppSettings("SmtpServer").ToString 'mail.xyz.com
    SmtpMail.Send(NewMail)
    NewMail.Dispose()
    SmtpMail.Dispose()
End Sub

Answer 1

用户名或密码必须不正确，请尝试使用不同的用户和密码，然后检查。}

还验证要连接的端口（eg. 587）