jmail.Message 错误 '8000ffff'

The message was undeliverable. All servers failed to receive the message

/sendmail.asp，行 19


这个错误提示是什么原因啊？怎么解决？

-----------------------源码----------------------------------
Function sendEmail(email,topic,mailbody)
on error resume next
dim JMail
Set JMail=Server.CreateObject("JMail.Message")
'JMail.silent=true
JMail.Logging=True
JMail.Charset="gb2312"
JMail.MailServerUserName = "帐号"
JMail.MailServerPassword = "密码"
JMail.ContentType = "text/html"
JMail.Priority = 1
JMail.From= "test@163.com"
JMail.FromName = "坏小子"
JMail.AddRecipient email
JMail.Subject=topic
JMail.Body=mailbody
JMail.Send ("mail.163.com")
Set JMail=nothing
sendEmail=True
If err then sendEmail=False
End Function

If sendEmail("badguycyh@hotmail.com","标题","测试") = False then
Response.Write "失败"
Else
Response.Write "成功！"
End If