ASP/VBScript- Send Big HTML EMail Failed ?

[carsonweb]

Below is my code to send HTML email from asp page. It works perfect for small, like 1kb html files(either I use HTMLBody, or CreateMHTMLBody), but for big html page like yahoo.com, even my test file 15kb, it just doesnot receive at all, nothing in badmail/queue/pickup... folders either.

I use IIS6.0+Windows Server 2003, I checked IIS settings. I already set "Limit Message Sizes" to 20MB.

Very frustrated. Please help...
'********************************
Set myMail=CreateObject("CDO.Message")

myMail.Subject=subjectString
myMail.From=send_fromStr
myMail.To=send_toStr

'myMail.HTMLBody= ReadTextFileLinebyLine(htmlpath)

''''''''''''''''''''''''''''''''''''''''''''''''
myMail.CreateMHTMLBody "http://www.yahoo.com", 0
''''''''''''''''''''''''''''''''''''''''''''''''

myMail.Configuration.Fields.Item ("http://schemas.microsoft.com/cdo/configuration/sendusing")=2
'Name or IP of remote SMTP server
myMail.Configuration.Fields.Item ("http://schemas.microsoft.com/cdo/configuration/smtpserver") ="x.x.x.x"
'Server port
myMail.Configuration.Fields.Item ("http://schemas.microsoft.com/cdo/configuration/smtpserverport") =25
myMail.Configuration.Fields.Update
myMail.Send
set myMail=nothing