QuoteCDOSendMail.c(90): error #2048: Undeclared identifier 'CLSID_IMessage' (did you mean 'CLSID_Message'?).
And that was correct too :)
I'm uncertain about this feature, but time will tell...
Sometimes it works well, like in this case, but if you forget an #include file there may be a message like:
Undeclare identifier 'abcd' (did you mean 'bob_for_president'?) -- or whatever. Less useful.