Creating Custom Simple Mapi DLL, fails when executing

Question

i need to create small dll to intercept simple mapi calls and send files via:

file->Send to as attachment (in excel, word, acrobat reader...) or via explorer->rightclickmenu->Send to->Mail recipient

to attach to gmail.

after reading this:

Mapi32.dll Stub Registry Settings (Windows)

Mapi32 Stub Library (Windows)

and searching here on stackoverflow and other webs i have created one very small dll using code::blocks that shows me information for investigating the process.

I have installed it on registry correctly like indicated in previous links on HKEY_LOCAL_MACHINE\SOFTWARE\Clients\Mail\SimpMapi.

I have selected on my win xp pro in control panel->Internet options my SimpMapi client.

when i open excel write some cells and go to File->Send like attachment dll shows me that first calls MapiLogon, second calls MapiSendMail and third when i close excel it calls MapiLogoff, but then it throws an error and closes excel.exe.

If i try it from explorer window right clicking one file and SendTo->Mail recipient it calls directly MapiSendMail and when i click on ok in MsgBox it throws an error and closes explorer.exe

Could you help me to find out what is wrong.

This is the mail.h file:

#ifndef __MAIN_H__
#define __MAIN_H__

#include <windows.h>

// Todo lo necesario a incluir por mapi.h
#define SUCCESS_SUCCESS         0
#define MAPI_E_USER_ABORT       1
#define MAPI_E_LOGIN_FAILURE    3

typedef unsigned long FLAGS;
typedef unsigned long LHANDLE;
typedef unsigned long FAR *LPLHANDLE, FAR *LPULONG;

typedef struct {
  ULONG ulReserved;
  ULONG ulRecipClass;
  LPSTR lpszName;
  LPSTR lpszAddress;
  ULONG ulEIDSize;
  LPVOID lpEntryID;
} MapiRecipDesc, *lpMapiRecipDesc;

typedef struct {
  ULONG ulReserved;
  ULONG flFlags;
  ULONG nPosition;
  LPSTR lpszPathName;
  LPSTR lpszFileName;
  LPVOID lpFileType;
} MapiFileDesc, *lpMapiFileDesc;

typedef struct {
  ULONG ulReserved;
  LPSTR lpszSubject;
  LPSTR lpszNoteText;
  LPSTR lpszMessageType;
  LPSTR lpszDateReceived;
  LPSTR lpszConversationID;
  FLAGS flFlags;
  lpMapiRecipDesc lpOriginator;
  ULONG nRecipCount;
  lpMapiRecipDesc lpRecips;
  ULONG nFileCount;
  lpMapiFileDesc lpFiles;
} MapiMessage, *lpMapiMessage;


/*  To use this exported function of dll, include this header
 *  in your project.
 */

#ifdef BUILD_DLL
    #define DLL_EXPORT __declspec(dllexport)
#else
    #define DLL_EXPORT __declspec(dllimport)
#endif

extern "C" void DLL_EXPORT SomeFunction(const LPCSTR sometext);

extern "C" ULONG DLL_EXPORT MAPILogon(ULONG_PTR ulUIParam,LPSTR lpszProfileName,LPSTR lpszPassword,FLAGS flFlags,ULONG ulReserved,LPLHANDLE lplhSession);
extern "C" ULONG DLL_EXPORT MAPILogoff(LHANDLE lhSession,ULONG_PTR ulUIParam,FLAGS flFlags,ULONG ulReserved);
extern "C" ULONG DLL_EXPORT MAPISendDocuments(ULONG_PTR ulUIParam,LPSTR lpszDelimChar,LPSTR lpszFilePaths,LPSTR lpszFileNames,ULONG ulReserved);
extern "C" ULONG DLL_EXPORT MAPISendMail(LHANDLE lhSession,ULONG_PTR ulUIParam,lpMapiMessage lpMessage,FLAGS flFlags,ULONG ulReserved);

#endif

This is the main.cpp file:

#include "main.h"

// a sample exported function
void DLL_EXPORT SomeFunction(const LPCSTR sometext)
{
    MessageBoxA(0, sometext, "DLL Message", MB_OK | MB_ICONINFORMATION);
}
ULONG DLL_EXPORT MAPILogon(ULONG_PTR ulUIParam,LPSTR lpszProfileName,LPSTR lpszPassword,FLAGS flFlags,ULONG ulReserved,LPLHANDLE lplhSession)
{
    MessageBoxA(0, "MAPILogon", "MAPILogon", MB_OK | MB_ICONINFORMATION);
    return SUCCESS_SUCCESS;
}
ULONG DLL_EXPORT MAPILogoff(LHANDLE lhSession,ULONG_PTR ulUIParam,FLAGS flFlags,ULONG ulReserved)
{
    MessageBoxA(0, "MAPILogoff", "MAPILogoff", MB_OK | MB_ICONINFORMATION);
    return SUCCESS_SUCCESS;
}
ULONG DLL_EXPORT MAPISendDocuments(ULONG_PTR ulUIParam,LPSTR lpszDelimChar,LPSTR lpszFilePaths,LPSTR lpszFileNames,ULONG ulReserved)
{
    MessageBoxA(0, "MAPISendDocuments", "MAPISendDocuments", MB_OK | MB_ICONINFORMATION);
    return SUCCESS_SUCCESS;
}
ULONG DLL_EXPORT MAPISendMail(LHANDLE lhSession,ULONG_PTR ulUIParam,lpMapiMessage lpMessage,FLAGS flFlags,ULONG ulReserved)
{
    MessageBoxA(0, "MAPISendMail", "MAPISendMail", MB_OK | MB_ICONINFORMATION);
    return SUCCESS_SUCCESS;
}
extern "C" DLL_EXPORT BOOL APIENTRY DllMain(HINSTANCE hinstDLL, DWORD fdwReason, LPVOID lpvReserved)
{
    switch (fdwReason)
    {
        case DLL_PROCESS_ATTACH:
            // attach to process
            // return FALSE to fail DLL load
            break;

        case DLL_PROCESS_DETACH:
            // detach from process
            break;

        case DLL_THREAD_ATTACH:
            // attach to thread
            break;

        case DLL_THREAD_DETACH:
            // detach from thread
            break;
    }
    return TRUE; // succesful
}

Thanks in advance.

Jorge

Answer 1

In link: Creating Custom Simple Mapi DLL, throws error when executing

Andy helped me to solve the problem that was incorrect calling convention.

Adding WINAPI to all my Simple MAPI function declarations and definitions it worked, example:

extern "C" ULONG DLL_EXPORT WINAPI MAPILogon( // etc

Then the problem was that my exported functions were exported with declarations.

To correct this in code::blocks you have to add in:

Main menu: Project -> Build options -> GNU GCC Compiler -> Linker settings -> Other linker options: -Wl,--kill-at

Thanks!