HOWTO: List Messages in the Inbox with MAPI

ID: Q239795


The information in this article applies to:
  • Extended Messaging Application Programming Interface (MAPI), version 1.0


SUMMARY

Extended MAPI can be used to access a Mailbox and manipulate messages. This article demonstrates how to use MAPI to list the messages contained within the Inbox.


MORE INFORMATION

The following sample code demonstrates how to use MAPI to list the messages contained within the Inbox.

  • Open Visual C++ and create a new Win32 Console Application.


  • Name the project "GetInbox".


  • Cut and paste the following code in the GetInbox.cpp file generated such that you replace the "main" procedure but leave the include files.


  • Add MAPI32.lib to the Project settings under the Link tab.


  • Compile and run the application.



   #include <stdio.h>
   #include <conio.h>
   #include <mapix.h>
   #include <mapiutil.h>

   STDMETHODIMP ListMessages(
   LPMDB lpMDB,
   LPMAPIFOLDER lpInboxFolder);

   STDMETHODIMP OpenDefaultMessageStore(
   LPMAPISESSION lpMAPISession,
   LPMDB * lpMDB);

   STDMETHODIMP OpenInbox(
   LPMDB lpMDB,
   LPMAPIFOLDER *lpInboxFolder);

   void main() 
   {
   HRESULT       hRes;
   LPMAPISESSION lpMAPISession = NULL;
   LPMDB         lpMDB = NULL;
   LPMAPIFOLDER  lpInboxFolder = NULL;
   LPSPropValue  tmp = NULL;

   hRes = MAPIInitialize(NULL);
   if (FAILED(hRes)) goto quit;

   hRes = MAPILogonEx(0,
      NULL,//profile name
      NULL,//password - This parameter should ALWAYS be NULL
      MAPI_LOGON_UI, //Allow a profile picker box to show if not logged in
      &lpMAPISession);//handle of session
   if (FAILED(hRes)) goto quit;

   hRes = OpenDefaultMessageStore(
      lpMAPISession,
      &lpMDB);
   if (FAILED(hRes)) goto quit;

   hRes = OpenInbox(
      lpMDB,
      &lpInboxFolder);
   if (FAILED(hRes)) goto quit;

   //Checking to see that we did get the Inbox
   hRes = HrGetOneProp(
      lpInboxFolder,
      PR_DISPLAY_NAME,
      &tmp);
   if (FAILED(hRes)) goto quit;
   printf("I managed to open the folder '%s'\n",tmp->Value.lpszA);

   hRes = ListMessages(
      lpMDB,
      lpInboxFolder);
   if (FAILED(hRes)) goto quit;

   quit:
   if (tmp) MAPIFreeBuffer(tmp);
   UlRelease(lpInboxFolder);
   UlRelease(lpMDB);
   UlRelease(lpMAPISession);
   MAPIUninitialize();
   if (FAILED(hRes))
   {
      printf("Failed with hRes of %x\n",hRes);		
   }
   printf("Hit any key to continue\n");
   while(!_kbhit()){ Sleep(50);};

   }

  STDMETHODIMP ListMessages(
   LPMDB lpMDB,
   LPMAPIFOLDER lpInboxFolder)
   {
   HRESULT hRes = S_OK;
   LPMAPITABLE lpContentsTable = NULL;
   LPSRowSet pRows = NULL;
   LPSTREAM lpStream = NULL;
   ULONG i;

   //You define a SPropTagArray array here using the SizedSPropTagArray Macro
   //This enum will allows you to access portions of the array by a name instead of a number.
   //If more tags are added to the array, appropriate constants need to be added to the enum.
   enum {
      ePR_SENT_REPRESENTING_NAME,
      ePR_SUBJECT,
      ePR_BODY,
      ePR_PRIORITY,
      ePR_ENTRYID,
      NUM_COLS};
   //These tags represent the message information we would like to pick up
   static SizedSPropTagArray(NUM_COLS,sptCols) = { NUM_COLS,
      PR_SENT_REPRESENTING_NAME,
      PR_SUBJECT,
      PR_BODY,
      PR_PRIORITY,
      PR_ENTRYID
   };

   hRes = lpInboxFolder->GetContentsTable(
      0,
      &lpContentsTable);
   if (FAILED(hRes)) goto quit;

    hRes = HrQueryAllRows(
      lpContentsTable,
      (LPSPropTagArray) &sptCols,
      NULL,//restriction...we're not using this parameter
      NULL,//sort order...we're not using this parameter
      0,
      &pRows);
   if (FAILED(hRes)) goto quit;

   for (i = 0; i < pRows -> cRows; i++)
   {
      LPMESSAGE lpMessage = NULL;
      ULONG ulObjType = NULL;
      LPSPropValue lpProp = NULL;

      printf("Message %d:\n",i);
      if (PR_SENT_REPRESENTING_NAME == pRows -> aRow[i].lpProps[ePR_SENT_REPRESENTING_NAME].ulPropTag)
      {   
         printf("From: %s\n",pRows->aRow[i].lpProps[ePR_SENT_REPRESENTING_NAME].Value.lpszA);
      }   
      if (PR_SUBJECT == pRows -> aRow[i].lpProps[ePR_SUBJECT].ulPropTag)
      {   
         printf("Subject: %s\n",pRows->aRow[i].lpProps[ePR_SUBJECT].Value.lpszA);
      }   
      if (PR_PRIORITY == pRows -> aRow[i].lpProps[ePR_PRIORITY].ulPropTag)
      {   
         printf("Priority: %d\n",pRows->aRow[i].lpProps[ePR_PRIORITY].Value.l);
      }   

   //the following method of printing PR_BODY will not always get the whole body
/*    if (PR_BODY == pRows -> aRow[i].lpProps[ePR_BODY].ulPropTag)
      {   
         printf("Body: %s\n",pRows->aRow[i].lpProps[ePR_BODY].Value.lpszA);
      }
*/ 

      //PR_BODY needs some special processing...
      //The table will only return a portion of the PR_BODY...if you want it all, we should
      //open the message and retrieve the property. GetProps (which HrGetOneProp calls
      //underneath) will do for most messages. For some larger messages, we would need to 
      //trap for MAPI_E_NOT_ENOUGH_MEMORY and call OpenProperty to get a stream on the body.

      if (MAPI_E_NOT_FOUND != pRows -> aRow[i].lpProps[ePR_BODY].Value.l)
      {
         hRes = lpMDB->OpenEntry(
            pRows->aRow[i].lpProps[ePR_ENTRYID].Value.bin.cb,
            (LPENTRYID) pRows->aRow[i].lpProps[ePR_ENTRYID].Value.bin.lpb,
            NULL,//default interface
            MAPI_BEST_ACCESS,
            &ulObjType,
            (LPUNKNOWN *) &lpMessage);
         if (!FAILED(hRes))
         {
            hRes = HrGetOneProp(
               lpMessage,
               PR_BODY,
               &lpProp);
            if (hRes == MAPI_E_NOT_ENOUGH_MEMORY)
            {
               char szBuf[255];
               ULONG ulNumChars;
               hRes = lpMessage->OpenProperty(
                  PR_BODY,
                  &IID_IStream,
                  STGM_READ,
                  NULL,
                  (LPUNKNOWN *) &lpStream);

               do
               {
                  lpStream->Read(
                     szBuf,
                     255,
                     &ulNumChars);
                  if (ulNumChars >0) printf("%.*s",ulNumChars,szBuf);
               }
               while (ulNumChars >= 255);

               printf("\n");

               hRes = S_OK;
            }
            else if (hRes == MAPI_E_NOT_FOUND)
            {
               //This is not an error. Many messages do not have bodies.
               printf("Message has no body!\n");
               hRes = S_OK;
            }
            else
            {
               printf("Body: %s\n",lpProp->Value.lpszA);
            }
         }
      }

      MAPIFreeBuffer(lpProp);
      UlRelease(lpMessage);
      hRes = S_OK;

   }

   quit:
   FreeProws(pRows);
   UlRelease(lpContentsTable);
   return hRes;
   }


   STDMETHODIMP OpenInbox(
   LPMDB lpMDB,
   LPMAPIFOLDER *lpInboxFolder)
   {
   ULONG        cbInbox;
   LPENTRYID    lpbInbox;
   ULONG        ulObjType;
   HRESULT      hRes = S_OK;
   LPMAPIFOLDER	lpTempFolder = NULL;
	
   *lpInboxFolder = NULL;

   //The Inbox is usually the default receive folder for the message store
   //You call this function as a shortcut to get it's Entry ID
   hRes = lpMDB->GetReceiveFolder(
      NULL,      //Get default receive folder
      NULL,      //Flags
      &cbInbox,  //Size and ...
      &lpbInbox, //Value of the EntryID to be returned
      NULL);     //You don't care to see the class returned
   if (FAILED(hRes)) goto quit;

   hRes = lpMDB->OpenEntry(
      cbInbox,                      //Size and...
      lpbInbox,                     //Value of the Inbox's EntryID
      NULL,                         //We want the default interface    (IMAPIFolder)
      MAPI_BEST_ACCESS,             //Flags
      &ulObjType,                   //Object returned type
      (LPUNKNOWN *) &lpTempFolder); //Returned folder
   if (FAILED(hRes)) goto quit;

   //Assign the out parameter
   *lpInboxFolder = lpTempFolder;

   //Always clean up your memory here!
   quit:
   MAPIFreeBuffer(lpbInbox);
   return hRes;
   }

   STDMETHODIMP OpenDefaultMessageStore(
   LPMAPISESSION lpMAPISession,
   LPMDB * lpMDB)
   {
   LPMAPITABLE pStoresTbl = NULL;
   LPSRowSet   pRow = NULL;
   static      SRestriction sres;
   SPropValue  spv;
   HRESULT     hRes;
   LPMDB       lpTempMDB = NULL;

   enum {EID, NAME, NUM_COLS};
   static SizedSPropTagArray(NUM_COLS,sptCols) = {NUM_COLS, PR_ENTRYID, PR_DISPLAY_NAME};

   *lpMDB = NULL;

   //Get the table of all the message stores available
   hRes = lpMAPISession -> GetMsgStoresTable(0, &pStoresTbl);
   if (FAILED(hRes)) goto quit;

   //Set up restriction for the default store
   sres.rt = RES_PROPERTY; //Comparing a property
   sres.res.resProperty.relop = RELOP_EQ; //Testing equality
   sres.res.resProperty.ulPropTag = PR_DEFAULT_STORE; //Tag to compare
   sres.res.resProperty.lpProp = &spv; //Prop tag and value to compare against

   spv.ulPropTag = PR_DEFAULT_STORE; //Tag type
   spv.Value.b   = TRUE; //Tag value

   //Convert the table to an array which can be stepped through
   //Only one message store should have PR_DEFAULT_STORE set to true, so only one will be returned
   hRes = HrQueryAllRows(
   pStoresTbl, //Table to query
   (LPSPropTagArray) &sptCols, //Which columns to get
   &sres, //Restriction to use
   NULL, //No sort order
   0, //Max number of rows (0 means no limit)
   &pRow); //Array to return
   if (FAILED(hRes)) goto quit;

   //Open the first returned (default) message store
   hRes = lpMAPISession->OpenMsgStore(
      NULL,//Window handle for dialogs
      pRow->aRow[0].lpProps[EID].Value.bin.cb,//size and...
      (LPENTRYID)pRow->aRow[0].lpProps[EID].Value.bin.lpb,//value of entry to open
      NULL,//Use default interface (IMsgStore) to open store
      MAPI_BEST_ACCESS,//Flags
      &lpTempMDB);//Pointer to place the store in
   if (FAILED(hRes)) goto quit;

   //Assign the out parameter
   *lpMDB = lpTempMDB;

   //Always clean up your memory here!
quit:
   FreeProws(pRow);
   UlRelease(pStoresTbl);
   if (FAILED(hRes))
   {
      HRESULT hr;
      LPMAPIERROR lpError; 
      hr = lpMAPISession->GetLastError(hRes,0,&lpError);
      if (!hr)
      {
         printf("%s\n%s\n",lpError->lpszError,lpError->lpszComponent);
         MAPIFreeBuffer(lpError);
      }
   }
   return hRes;
   } 


REFERENCES

Please see the following article in the Microsoft Knowledge Base on retrieving messages based on a particular criteria using MAPI and EDK functions:

Q200181 HOWTO: Retrieve Messages Based on a Particular Criteria

Additional query words:

Keywords : kbfile kbMAPI kbMsg kbfaq kbGrpMsg kbDSupport
Version : WINDOWS:1.0
Platform : WINDOWS
Issue type : kbhowto


Last Reviewed: December 3, 1999
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