Now I find the place where the message stores the UIDL message ids.

Using OutlookSpy, selete a message, then click IMessage button. In "Property
Tag" list of "GetProps" tab, 0x8016 (|ID=0x8f01) is UIDL message ids. The
BINARY value can be parsed to "POP://xxxxxxxx".

I use CDO and OOM and have not used MAPI yet. Do you think using MAPI is the
only way to get this value? Could you give me some example of using MAPI?

I googled and found your another article which said to add these lines:
#define INITGUID
#include objbase.h

#define USES_IID_IMessage

#include mapix.h
#include mapitags.h
#include mapidefs.h
#include mapiutil.h
#include mapiguid.h

These are codes in my program:
CComPtr IUnknown spUnknown;
CComPtr IMessage spIMessage;
spNewMail-get_MAPIOBJECT(&spUnknown); // point to a message
spUnknown-QueryInterface(IID_IMessage, (void **)&spIMessage);

I get two link errors:
error LNK2001: unresolved external symbol _IID_IMessage
fatal error LNK1120: 1 unresolved externals

Could you tell me how to resolve it? Thank you. :-)


"Dmitry Streblechenko" wrote:

No, it does not delete the message id.
Yes, you can access the list of message ids. If you are using CDO 1.21, use
the Folder.HiddenMessages to find the corresponding message. Look at the
hidden messages with OutlookSpy (click IMAPIFolder, go to the "Associated
Contents" tab) or MFCMAPI.
I don't see however how that will help you - if you delete that message id,
POP3 provider will assume that it is a new message and download it again.
This is the opposite of what you are trying to achieve.

Dmitry Streblechenko (MVP)
http://www.dimastr.com/
OutlookSpy - Outlook, CDO
and MAPI Developer Tool

"Rui Feng" wrote in message
...
So do you think CDO "Message.Delete" method does not delete (maybe forget
to
delete) message ids in that hidden message? If this is true, can my add-in
access that hidden message in the Inbox and delete ids?

Thank you.

"Dmitry Streblechenko" wrote:

Outlook stores the list of the message ids in a hidden message
(PR_MESSAGE_CLASS = "IPM.MessageManager") in the Inbox.
However there is no way to tell the POP3 provider in Outlook to delete a
particular message from a POP3 server.

Dmitry Streblechenko (MVP)
http://www.dimastr.com/
OutlookSpy - Outlook, CDO
and MAPI Developer Tool

"Rui Feng" Rui wrote in message
...
Hi all.

My Outlook 2003 retrieves emails from a POP3 server. I set to "Leave a
copy
of messages on the server" and "Remove from server when deleted from
'Deleted Items'". I wrote a COM Add-in using VC++ 6.0

When recieved a new mail from certain sender, I can catch the
ItemAdd event and use CDO Message-Delete() to permanently delete that
new email. But the email has not been deleted from the POP3 server.

I guess there is a looking-up table in Outlook. When I delete an Email
in
"Deleted Items Folder", Outlook find ID of that email and set a value.
It
uses that value to notify the POP3 server next time to delete
corresponding
email
with the same ID on the server.

I think maybe CDO doesn't tell Outlook that "an email was deleted and
please
tell
POP3 Server to delete the copy when connected next time".

Is that true and how to solve it? If you can do it using other
programming
language
like VB please tell me anyway.

Thank you. :-)

--------
Beijing, China