服务器拒绝了发件人地址。服务器响应为: 553
邮件发送失败, 错误编号: 服务器拒绝了发件人地址。服务器响应为: 553 authentication is required,smtp11,D8CowEBJYV7frmdR5Tf6AA--.543S2 1365749471

求解决，菜鸟不懂
代码如下

Set myMail=server.CreateObject("CDO.Message")

			

			myMail.Subject="Sending email with CDO"

			myMail.From="xiayuxuan91@163.com"

			myMail.To="253305452@qq.com"

			myMail.TextBody="This is a message."

			myMail.Configuration.Fields.Item _

			("http://schemas.microsoft.com/cdo/configuration/sendusing")=2

			'远程 SMTP 服务器的 IP 或名称

			

			myMail.Configuration.Fields.Item _

			("http://schemas.microsoft.com/cdo/configuration/smtpserver") _

			="smtp.163.com"

			'服务器端口

			myMail.Configuration.Fields.Item _

			("http://schemas.microsoft.com/cdo/configuration/smtpserverport") _

			=25 

			myMail.Configuration.Fields.Item _

			(" http://schemas.microsoft.com/cdo/configuration/sendusername")_

			="xiayuxuan91" '用户名

			myMail.Configuration.Fields.Item _

			(" http://schemas.microsoft.com/cdo/configuration/sendpassword")_

			="**************" '密码

			myMail.Configuration.Fields.Item _

			(" http://schemas.microsoft.com/cdo/configuration/smtpauthenticate")_

			=1

			myMail.Configuration.Fields.Item _

			(" http://schemas.microsoft.com/cdo/configuration/smtpusessl")_

			=false

			myMail.Configuration.Fields.Update

			myMail.Send	

总提示服务器拒绝
------解决方案--------------------
            myMail.Configuration.Fields.Item _
            (" http://schemas.microsoft.com/cdo/configuration/smtpaccountname")_
            ="xiayuxuan91@163.com" 
            myMail.Configuration.Fields.Item _
            (" http://schemas.microsoft.com/cdo/configuration/sendusername")_
            ="xiayuxuan91" '用户名

加红色的部分试试