CDOSYS : how to check if it's working?

On a client server, we have a little script that send an email at the end of an order, just before closing it.

Until yesterday everything works fine, but suddenly, the page gives a generic 500 error. so I start from the bottom of the page find that if I put a response.end just before the .send of the cdo mail function, the page works fine:

Set iMsg = CreateObject("CDO.Message")
Set iConf = CreateObject("CDO.Configuration")
Set Flds = iConf.Fields

Flds(cdoSendUsingMethod) = cdoSendUsingPort
Flds(cdoSMTPServer) = "mail.theserver.com" 
Flds(cdoSMTPServerPort) = 25
Flds(cdoSMTPAuthenticate) = cdoAnonymous '0
Flds.Update             

With iMsg
    Set .Configuration = iConf                        
         .To = "[email protected]"
         .From = "[email protected]"
         .Sender = ""
         .Subject = "test"                   
         .HTMLBody = "TEST"
         RESPONSE.END()
         .Send
End With

On the page there are also two lines at the beginning:

<!--METADATA TYPE="typelib" UUID="CD000000-8B95-11D1-82DB-00C04FB1625D" NAME="CDO for Windows 2000 Type Library" -->
<!--METADATA TYPE="typelib" UUID="00000205-0000-0010-8000-00AA006D2EA4" NAME="ADODB Type Library" -->

Well, I’ve already done some test putting some script to send emails a little different from this one but nothing seems to work. Does anybody know a way to test the cdosys? Something that. I don't know, return the version... or a list of options... well, something that makes me know that the error is on the server (and so I could phone to them and tell "hey it's not my fault")...?

Edit: Since the page gives only a 500 error, is there a way to makes the server returns a more specific error code? i can't access the server, but only the ftp (so only classic asp)

Edit 2: i have add this code:

on error resume next
.Send
If Err.Number <> 0 Then
Response.write(Err.Number)
response.write("<br>")
response.write(Err.description)
end if

and it gives this message:

-2147220975 Impossibile inviare il messaggio al server SMTP. Codice errore di trasporto: 0x800ccc6f. Risposta del server: 554 Your access to this mail system has been rejected due to the sending MTA's poor reputation.

Solution

Based on your error message the CDO component is working but your SMTP sever (MTA) is rejecting the message. Maybe because of the .gov domain? Regardless you have a poor SMTP reputation for spamming. You need to use a different SMTP server. If you are using the ip of the IIS server, than that IP is no longer good, and has been blacklisted by spam servers.

Mailchimp has a lot of information on mail deliverable. Take a look at it. You can use a hosted SMTP service (mailgun, sendgrid, mandrill), all of which will block you right away if you are spamming.