Reading and Writing Messages in Outlook Express

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• Download demo project - 19.1 Kb

Table of contents

• Introduction
• Using this Code
• Points of Interest
  • List local folders
  • List messages of a folder
  • Display the source of a message
  • Create a message in a folder
  • List body properties
  • List attachments
  • Get body content
  • Set body content
• License
• History

Introduction

The application has the following features:

1. List local folders.
2. Create / rename / delete local folder.
3. List messages of a local folder.
4. Get message properties.
5. Get message source.
6. Create / copy / move / delete messages.
7. Mark messages as Read or Unread.
8. List body properties or headers.
9. Get / set property values.
10. Navigate body structure.
11. Get / set body content.
12. Insert bodies.
13. List / add / remove attachments.

Using this Code

This code was written to provide an initial example of the IStoreFolder / IStoreNamespace classes. Then, an example of IMimeMessage / IMimeMessageTree / IMimeBody / IMimePropertySet was added to the application. The idea of this article is to document, with a complete example, all these interfaces to show how Outlook Express storage could be accessed.

In the initial dialog, all the local folders of the main identity are listed to let the user modify them. In the message dialog, you will see all the messages of the selected folder. Identifying the message source and other operations can be done here. In the 'Bodies' dialog, you will be able to view the message structure and modify it.

Points of Interest

List local folders:

// add all the folders to the list box recursively
void CDemoDlg::AddFolders(STOREFOLDERID dwFolderId)
{
    FOLDERPROPS props;
    HENUMSTORE hEnum;
    int nIndex;

    hEnum = NULL;

    // set the size of the structure
    // or the function return error
    props.cbSize = sizeof(FOLDERPROPS);

    HRESULT hr = 
      m_pStoreNamespace->GetFirstSubFolder(dwFolderId, 
      &props, &hEnum);

    while(SUCCEEDED(hr) && hr != 
               S_FALSE && hEnum != NULL) {
        nIndex = m_listFolder.AddString(props.szName);

        if(nIndex != LB_ERR && nIndex != LB_ERRSPACE) {
            // set the folder id as the data of the item
            m_listFolder.SetItemData(nIndex, props.dwFolderId);

            // add children of this folder too
            AddFolders(props.dwFolderId);
        }

        hr = m_pStoreNamespace->GetNextSubFolder(hEnum, &props);
    }

    // close the enum
    if(hEnum) {
        m_pStoreNamespace->GetSubFolderClose(hEnum);
    }
}

List messages of a folder:

//List messages of folder and add 
//all 'Subject' and 'From' to the list box
MESSAGEPROPS msgProps;
HENUMSTORE hEnumMsg;
CString item;
int nIndex;

hEnumMsg = NULL;

// set the size of the structure
// or the function return error
msgProps.cbSize = sizeof(MESSAGEPROPS);

// as we want the subject and other
// staff we get all the properties.
// you can use MSGPROPS_FAST as first parameter
// to get only a few properties of the message.
HRESULT hr = m_pStoreFolder->GetFirstMessage(0,
                                             0,
                                             MESSAGEID_FIRST,
                                             &msgProps,
                                             &hEnumMsg);

while(SUCCEEDED(hr) && hr != S_FALSE) {
    item = msgProps.pszDisplayFrom;
    item += _T("      ");
    item += msgProps.pszNormalSubject;

    // message subject and from is displayed in the list box.
    // data of each item is the message id.
    nIndex = m_listMsg.AddString(item);

    if(nIndex != LB_ERR && nIndex != LB_ERRSPACE) {
        m_listMsg.SetItemData(nIndex, msgProps.dwMessageId);
    }

    // free the message properties
    // as they are allocated by IStoreFolder.
    m_pStoreFolder->FreeMessageProps(&msgProps);

    hr = m_pStoreFolder->GetNextMessage(hEnumMsg, 
                                   0, &msgProps);
}

// close the enum
if(hEnumMsg) {
    m_pStoreFolder->GetMessageClose(hEnumMsg);
}

Display the source of a message:

// this function displays the source
// of the selected message in the list box
void CMsgDlg::OnView()
{
    ULONG ulReaded = 0;
    int nIndex;
    STOREFOLDERID dwSelMsg;
    HRESULT hr;
    IStream *pTextStream;
    char buffer[4096];

    // Get selected folder id
    nIndex = m_listMsg.GetCurSel();
    if(nIndex == LB_ERR) {
        MessageBox(_T("Select a message first."), 
                   _T("Demo Error"));
        return;
    }

    dwSelMsg = m_listMsg.GetItemData(nIndex);

    // create a IStream from the message
    hr = m_pStoreFolder->OpenMessage(dwSelMsg, 
         IID_IStream, (VOID **) &pTextStream);
    if(FAILED(hr)) {
        MessageBox(_T("Error opening message."), 
                   _T("Demo Error"));
        return;
    }

    CMsgSrcDlg msgSrcDlg;

    // read all the message
    do {
        hr = pTextStream->Read(buffer, 
             sizeof(buffer)-1, &ulReaded);

        if(FAILED(hr)) {
            MessageBox(_T("Error reading message."), 
                       _T("Demo Error"));
        }
        else {
            buffer[ulReaded] = 0;

            msgSrcDlg.AddMessageSource(buffer);
        }
    } while(SUCCEEDED(hr) && ulReaded != 0);

    if(SUCCEEDED(hr)) {
        // display message
        msgSrcDlg.DoModal();
    }

    pTextStream->Release();
}

Create a message in a folder:

IStream *newMail = NULL;
MESSAGEID msgId;
HRESULT hr;
ULONG len;
CString msgSource;

// Set msgSource to contain
// the source of the new message
...

// Create the IStream to write the new message
// this function returns the id of the new message
hr = m_pFolder->CreateStream(0, 0, &newMail, &msgId);
if(FAILED(hr)) {
    MessageBox(_T("Cannot Create Stream."), 
               _T("Demo Error"));
    return;
}

// write message source in the IStream
hr = newMail->Write((const char *) msgSource, 
     msgSource.GetLength(), &len);
if(FAILED(hr)) {
    MessageBox(_T("Cannot Write message."), 
               _T("Demo Error"));
    newMail->Release();
    return;
}

// Commit the IStream in the folder
// and use the returned msgId
hr = m_pFolder->CommitStream(0, 0, 0, 
                  newMail, msgId, NULL);
if(FAILED(hr)) {
    MessageBox(_T("Cannot Commit Stream."), 
               _T("Demo Error"));
    newMail->Release();
    return;
}

// release the IStream
newMail->Release();

List body properties:

// add property names to the combo box
// first get IMimeMessage interface
// using IStoreFolder and the message id.
hr = pFolder->OpenMessage(msgId,
                          IID_IMimeMessage,
                          (LPVOID*) &m_pMimeMsg);
if(FAILED(hr)) {
    OutputDebugString("CMessageTreeDlg::"
             "SetMessage: OpenMessage.\n");
    return;
}

// get root body of the message.
hr = m_pMimeMsg->GetBody(IBL_ROOT, 0, &m_hCurBody);
if(FAILED(hr)) {
    OutputDebugString("OEMessage::SetMessage:"
                      " Cannot get root body.\n");
    return;
}

...

// bind the body to the IMimePropertySet interface.
hr = m_pMimeMsg->BindToObject(m_hCurBody,
     IID_IMimePropertySet, (LPVOID *) &m_pPropertySet);
if(FAILED(hr)) {
    OutputDebugString("OEMessage::UpdateBodyInfo:"
           " BindToObject IID_IMimePropertySet.\n");
    return;
}

...

IMimeEnumProperties *pEnum = NULL;
ENUMPROPERTY eProp = {0};
ULONG cFetched;
HRESULT hr;

m_propNames.ResetContent();

// enum properties of the body.
hr = m_pPropertySet->EnumProps(0, &pEnum);
if(FAILED(hr)) {
    OutputDebugString("OEMessage::"
          "FillCombo: EnumProps.\n");
    return;
}

hr = pEnum->Next(1, &eProp, &cFetched);

while(SUCCEEDED(hr) && hr != S_FALSE) {
    m_propNames.AddString(eProp.pszName);

    hr = m_pAllocator->FreeEnumPropertyArray(1,
                                    &eProp, FALSE);
    if(FAILED(hr)) {
        OutputDebugString("OEMessage::FillCombo:"
                          " FreeEnumPropertyArray.\n");
    }

    hr = pEnum->Next(1, &eProp, &cFetched);
}

if(pEnum) {
    pEnum->Release();
}

List attachments:

ULONG attachCount, i, j;
HBODY *bodyAttachs = NULL;
HRESULT hr;
IMimeBody *pMimeBody;
LPSTR display;
int nItem;

m_attachs.ResetContent();

hr = m_pMimeMsg->GetAttachments(&attachCount,
                                   &bodyAttachs);
if(FAILED(hr)) {
    MessageBox(_T("Cannot get attachments:")
       _T(" GetAttachments."), _T("Demo Error"), MB_OK);
    return;
}

// keep only bodies of type IBT_ATTACHMENT.
for(i=0; i<attachCount;) {
    hr = m_pMimeMsg->IsBodyType(bodyAttachs[i],
                                  IBT_ATTACHMENT);
    if(hr != S_OK) {
        for(j=i+1; j<attachCount; j++) {
            bodyAttachs[j-1] = bodyAttachs[j];
        }

        attachCount--;
    }
    else {
        // for the attachments, get display
        // name of the body to add to the listbox.
        hr = m_pMimeMsg->BindToObject(bodyAttachs[i],
                                      IID_IMimeBody,
                                      (LPVOID *) &pMimeBody);
        if(SUCCEEDED(hr)) {
            hr = pMimeBody->GetDisplayName(&display);
            if(SUCCEEDED(hr)) {
                nItem = m_attachs.AddString(display);
                m_attachs.SetItemData(nItem,
                          (DWORD) bodyAttachs[i]);

                CoTaskMemFree(display);
            }
        }

        i++;
    }
}

if(bodyAttachs) {
    CoTaskMemFree(bodyAttachs);
}

Get body content:

while(1) { // just to save code!
    // bind body handle to a IMimeBody interface.
    hr = m_pMimeMsg->BindToObject(m_hCurBody,
                                  IID_IMimeBody,
                                  (LPVOID *) &pMimeBody);
    if(FAILED(hr)) {
        OutputDebugString("CMessageTreeDlg::"
             "UpdateBodyInfo: BindToObject\n");
        break;
    }

    ...

    encType = IET_BINARY;
    m_isTextBody = FALSE;

    m_cntType = GetContentType(m_hCurBody);

    // if the body is a 'text' treat as a text.
    // Otherwise, read it as a buffer char
    // by char.
    if(m_cntType.Find(_T("text")) == 0) {
        encType = IET_UNICODE;
        m_isTextBody = TRUE;
    }

    ...

    m_bodyContent = _T("");

    // Get body as a stream
    hr = pMimeBody->GetData(IET_UNICODE,
                            &pBodyStream);
    if(FAILED(hr)) {
        OutputDebugString("OEMessage::GetBodyText: GetData\n");
        break;
    }

    // if it is a text when we read it it comes unicode.
    if(encType == IET_UNICODE) {
        // for text bodies
        do {
            // Read the IStream into our buffer
            hr = pBodyStream->Read(lpszwBody,
                                   sizeof(lpszwBody)-sizeof(WCHAR),
                                   &ulRead);
            if(FAILED(hr)) {
                OutputDebugString("OEMessage::GetBodyText: Read\n");
            }
            else if(ulRead != 0) {
                // Null terminate it
                lpszwBody[ulRead/2] = '\0';
                m_bodyContent += (WCHAR *) lpszwBody;
            }
        } while(ulRead != 0);
    }
    else {
        do {
            // Read the IStream into our buffer.
            // It can be binary so it could
            // be displayed truncated.
            hr = pBodyStream->Read(lpszBody,
                                   sizeof(lpszBody)-sizeof(char),
                                   &ulRead);
            if(FAILED(hr)) {
                OutputDebugString("OEMessage::GetBodyText: Read\n");
            }
            else if(ulRead != 0) {
                // Null terminate it
                lpszBody[ulRead] = '\0';
                m_bodyContent += lpszBody;
            }
        } while(ulRead != 0);
    }

    pBodyStream->Release();

    break;
}

if(pMimeBody) {
    pMimeBody->Release();
}

Set body content:

HRESULT hr;
ULONG ulLength, ulWritten;
BSTR bstr = NULL;
IStream *pStream = NULL;
IMimeBody *pMimeBody = NULL;
PROPVARIANT propValue;

UpdateData(TRUE);

while(1) {
    // Create a new stream to write in the new body
    hr = CreateStreamOnHGlobal(NULL,
                               TRUE,
                               &pStream);
    if(FAILED(hr)) {
        MessageBox(_T("Cannot set content:" )
            _T(" CreateStreamOnHGlobal."),
            _T("Demo Error"), MB_OK);
        break;
    }

    // compute the new body length + the
    // zero that terminates the string
    ulLength = m_bodyContent.GetLength() + 1;

    // there are better ways
    // to do it but this is the easiest
    bstr = m_bodyContent.AllocSysString();

    // write in the new body
    hr = pStream->Write((LPWSTR) bstr,
                        ulLength * sizeof(WCHAR),
                        &ulWritten);
    if(FAILED(hr)) {
        MessageBox(_T("Cannot set content: Write."),
                   _T("Demo Error"), MB_OK);
        break;
    }

    // Commit the stream
    hr = pStream->Commit(STGC_DEFAULT);
    if(FAILED(hr)) {
        MessageBox(_T("Cannot set content: Commit."),
                   _T("Demo Error"), MB_OK);
        break;
    }

    // bind body handle to IMimeBody interface
    hr = m_pMimeMsg->BindToObject(m_hCurBody,
                                  IID_IMimeBody,
                                  (LPVOID *) &pMimeBody);
    if(FAILED(hr)) {
        MessageBox(_T("Cannot set content:")
                _T(" Commit."), _T("Demo Error"), MB_OK);
        break;
    }

    CString priCon, secCon;

    propValue.vt = VT_LPSTR;

    // get content-type property to save the body
    hr = m_pMimeMsg->GetBodyProp(m_hCurBody,
         PIDTOSTR(PID_HDR_CNTTYPE), 0, &propValue);
    if(FAILED(hr) || hr == S_FALSE) {
        MessageBox(_T("Cannot set content:")
             _T(" GetBodyProp."), _T("Demo Error"), MB_OK);
        break;
    }

    // this property has the format
    // of 'primaryType/secondaryType'
    char *sep = strchr(propValue.pszVal, '/');

    if(sep == NULL) {
        MessageBox(_T("Cannot set content:")
             _T("Content Type error."),
             _T("Demo Error"), MB_OK);
        PropVariantClear(&propValue);
        break;
    }

    secCon = sep+1;
    *sep = 0;
    priCon = propValue.pszVal;

    PropVariantClear(&propValue);

    // save the data in this new stream
    // into the body using
    // the save conent-type it had before
    hr = pMimeBody->SetData(IET_UNICODE,
                            priCon,
                            secCon,
                            IID_IStream,
                            pStream);
    if(FAILED(hr)) {
        MessageBox(_T("Cannot set content: SetData."),
                   _T("Demo Error"), MB_OK);
        break;
    }

    break;
}

if(bstr) {
    ::SysFreeString(bstr);
}
if(pMimeBody) {
    pMimeBody->Release();
}
if(pStream) {
    pStream->Release();
}

License

You can use this freely, leaving the copyright notice at the top of the files.

History

• 28-Dec-2004 - First released: IStoreFolder / IStoreNamespace.
• 25-Mar-2006 - Update: IMimeMessage / IMimeMessageTree / IMimePropertySet / IMimeBody.