CDO.Message Error on IIS 8.5

Hi all, I recently have an application that has shifted from IIS 7 to IIS 8.5.

There's a function that has CDO Message Problem. 

 error '8004020f'

 line 214

The error line is highlighted below: 

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")="<company's smtp server>"
'Server port
myMail.Configuration.Fields.Item _
("http://schemas.microsoft.com/cdo/configuration/smtpserverport")=25 
myMail.Configuration.Fields.UpdatemyMail.Send
set myMail=nothing

What could be the problem? What user configurations should we make to the server? We're running on Windows Server 2013. 

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")="confermail.ntu.edu.sg"
'Server port
myMail.Configuration.Fields.Item _
("http://schemas.microsoft.com/cdo/configuration/smtpserverport")=25
myMail.Configuration.Fields.Update
myMail.Send
set myMail=nothing