Not getting MIME data properly by using MIMEGetEntityData() method of IBM lotus notes c api toolkit

Question

I am trying to get the MIME data for fetching boundary, headers and body from Note Item. I am using MIMEGetEntityData() method of IBM lotus notes c api toolkit declared in "mimedir.h". But when I implemented it I am getting only HTML body part. Below is the implementation snippet:

    if (error = MIMEOpenDirectory(hNote, &hMIMEDir))
    {
        goto exit;
    }

    if (error = MIMEGetRootEntity(hNote, &pRootEntity))
    {
        goto exit;
    }

    while (TRUE) 
    {
        if (error = MIMEGetEntityData(hNote
                    pRootEntity,
                    MIME_ENTITY_DATA_RFC822TEXT, /*get all of the data for the entity -- boundary, headers, and body*/
                    dwOffset,
                    dwChunkLen,
                    &hData,
                    &dwDataLen))
        {
            if (error == ERR_NO_MIME_DATA) 
            {
                break;
            }
            goto exit;
        }

        pData = OSLock(char, hData);

        /* writing data to file
        ...
        */
        dwOffset += dwDataLen;
        OSUnlockAndFree(hData);
    }

Does anyone have any experience with this problem? Or can suggest how to get full MIME data content including header and body? Or any other way to do this?