Retrieve Email from Exchange Server with Web Service (EWS) in Visual C++

In previous section, I introduced how to retrieve email from IMAP4 server. In this section, I will introduce the Exchange Web Service (EWS) protocol (Exchange 2007-2019/Office365).

Introduction

Exchange Web Service (EWS) protocol is similar with IMAP4 protocol. First of all, it supports retrieving email from different mail folder and folder management. Secondly, Exchange Web Service supports mail read flag management. Therefore, we can do more things with Exchange server. To better understand the Exchange Web Service protocol, please see the following examples.

Exchange Server supports POP3/IMAP4 protocol as well, but in Exchange 2007 or later version, POP3/IMAP4 service is disabled by default. If you don’t want to use POP3/IMAP4 to download email from Exchange Server, you can use Exchange Web Service (Exchange 2007/2010/2013/2016 or later version) or WebDAV (Exchange 2000/2003) protocol.

Office 365 also supports EWS protocol.

Note

Remarks: All of examples in this section are based on first section: A simple Visual C++ project. To compile and run the following example codes successfully, please click here to learn how to create the test project and add reference to your project.

[Visual C++ Example - Retrieve email from Exchange INBOX]

The following example codes demonstrate how to download email from Exchange 2007/2010/2013/2016 server default mailbox using EWS protocol. In order to run it correctly, please change email server, user, password, folder, file name values.

Note

To get the full sample projects, please refer to Samples section.

#include "stdafx.h"
#include <Windows.h>

#include "EAGetMailobj.tlh"
using namespace EAGetMailObjLib;

DWORD  _getCurrentPath(LPTSTR lpPath, DWORD nSize)
{
    DWORD dwSize = ::GetModuleFileName(NULL, lpPath, nSize);
    if (dwSize == 0 || dwSize == nSize)
    {
        return 0;
    }

    // Change file name to current full path
    LPCTSTR psz = _tcsrchr(lpPath, _T('\\'));
    if (psz != NULL)
    {
        lpPath[psz - lpPath] = _T('\0');
        return _tcslen(lpPath);
    }

    return 0;
}

int _tmain(int argc, _TCHAR* argv[])
{
    const int MailServerPop3 = 0;
    const int MailServerImap4 = 1;
    const int MailServerEWS = 2;
    const int MailServerDAV = 3;
    const int MailServerMsGraph = 4;

    // Initialize COM environment
    ::CoInitialize(NULL);

    // Create a folder named "inbox" under current exe file directory
    // to save the emails retrieved.

    TCHAR szPath[MAX_PATH + 1];
    _getCurrentPath(szPath, MAX_PATH);

    TCHAR szMailBox[MAX_PATH + 1];
    wsprintf(szMailBox, _T("%s\\inbox"), szPath);

    // Create a folder to store emails
    ::CreateDirectory(szMailBox, NULL);

    try
    {
        IMailServerPtr oServer = NULL;
        oServer.CreateInstance(__uuidof(EAGetMailObjLib::MailServer));

        // Please use domain\user as the user name or full email address
        oServer->Server = _T("exch.emailarchitect.net");

        oServer->User = _T("tester@emailarchitect.net");
        oServer->Password = _T("testpassword");
        oServer->Protocol = MailServerEWS;

        // By default, Exchange Web Service (EWS) requires SSL connection
        // Please ignore Port property for EWS and WebDAV protocol
        oServer->SSLConnection = VARIANT_TRUE;

        IMailClientPtr oClient = NULL;
        oClient.CreateInstance(__uuidof(EAGetMailObjLib::MailClient));
        oClient->LicenseCode = _T("TryIt");

        oClient->Connect(oServer);
        _tprintf(_T("Connected\r\n"));

        IMailInfoCollectionPtr infos = oClient->GetMailInfoList();
        _tprintf(_T("Total %d emails\r\n"), infos->Count);

        for (long i = 0; i < infos->Count; i++)
        {
            IMailInfoPtr pInfo = infos->GetItem(i);

            TCHAR szFile[MAX_PATH + 1];
            // Generate a random file name by current local datetime,
            // You can use your method to generate the filename if you do not like it
            SYSTEMTIME curtm;
            ::GetLocalTime(&curtm);
            ::wsprintf(szFile, _T("%s\\%04d%02d%02d%02d%02d%02d%03d%d.eml"),
                szMailBox,
                curtm.wYear,
                curtm.wMonth,
                curtm.wDay,
                curtm.wHour,
                curtm.wMinute,
                curtm.wSecond,
                curtm.wMilliseconds,
                i);

            // Receive email from POP3 server
            IMailPtr oMail = oClient->GetMail(pInfo);

            // Save email to local disk
            oMail->SaveAs(szFile, VARIANT_TRUE);

            // Mark email as deleted from POP3 server.
            oClient->Delete(pInfo);
        }

        // Delete method just mark the email as deleted,
        // Quit method expunge the emails from server exactly.
        oClient->Quit();
    }
    catch (_com_error &ep)
    {
        _tprintf(_T("Error: %s"), (const TCHAR*)ep.Description());
    }

    return 0;
}

Because Exchange Web Service protocol supports folder access, so we can retrieve email from other mailbox rather than default “INBOX”. POP3 protocol doesn’t support this feature.

[Visual C++ Example - Retrieve email from “Deleted Items”]

The following example codes demonstrate how to retrieve emails from “Deleted Items” in an Exchange account.

Note

To get the full sample projects, please refer to Samples section.

#include "stdafx.h"
#include <Windows.h>

#include "eagetmailobj.tlh"
using namespace EAGetMailObjLib;

IImap4FolderPtr FindFolder(LPCTSTR folderPath, IFolderCollectionPtr& folders)
{
    for(long i = 0; i < folders->Count; i++)
    {
        IImap4FolderPtr oFolder = folders->GetItem(i);
        if(_tcsicmp((TCHAR*)oFolder->LocalPath, folderPath) == 0)
        {
            return oFolder;
        }

        IFolderCollectionPtr subFolders = oFolder->SubFolderList;
        oFolder = FindFolder(folderPath, subFolders);
        if(oFolder != NULL)
        {
            return oFolder;
        }
    }

    return NULL;
}

DWORD  _getCurrentPath(LPTSTR lpPath, DWORD nSize)
{
    DWORD dwSize = ::GetModuleFileName(NULL, lpPath, nSize);
    if (dwSize == 0 || dwSize == nSize)
    {
        return 0;
    }

    // Change file name to current full path
    LPCTSTR psz = _tcsrchr(lpPath, _T('\\'));
    if (psz != NULL)
    {
        lpPath[psz - lpPath] = _T('\0');
        return _tcslen(lpPath);
    }

    return 0;
}

int _tmain(int argc, _TCHAR* argv[])
{
    const int MailServerPop3 = 0;
    const int MailServerImap4 = 1;
    const int MailServerEWS = 2;
    const int MailServerDAV = 3;
    const int MailServerMsGraph = 4;

    // Initialize COM environment
    ::CoInitialize(NULL);

    // Create a folder named "inbox" under current exe file directory
    // to save the emails retrieved.

    TCHAR szPath[MAX_PATH + 1];
    _getCurrentPath(szPath, MAX_PATH);

    TCHAR szMailBox[MAX_PATH + 1];
    wsprintf(szMailBox, _T("%s\\inbox"), szPath);

    // Create a folder to store emails
    ::CreateDirectory(szMailBox, NULL);

    try
    {
        IMailServerPtr oServer = NULL;
        oServer.CreateInstance(__uuidof(EAGetMailObjLib::MailServer));

        // Please use domain\user as the user name or full email address
        oServer->Server = _T("exch.emailarchitect.net");

        oServer->User = _T("tester@emailarchitect.net");
        oServer->Password = _T("testpassword");
        oServer->Protocol = MailServerEWS;

        // By default, Exchange Web Service (EWS) requires SSL connection
        // Please ignore Port property for EWS and WebDAV protocol
        oServer->SSLConnection = VARIANT_TRUE;

        IMailClientPtr oClient = NULL;
        oClient.CreateInstance(__uuidof(EAGetMailObjLib::MailClient));
        oClient->LicenseCode = _T("TryIt");

        oClient->Connect(oServer);
        _tprintf(_T("Connected\r\n"));

        IFolderCollectionPtr folders = oClient->GetFolderList();
        // If you want search sub folder, use parentfolder\subfolder
        // For example: INBOX\\MySubFolder
        IImap4FolderPtr oFolder = FindFolder(_T("Deleted Items"), folders);

        if(oFolder == NULL)
        {
            _tprintf(_T("Error: folder not found!"));
            return 0;
        }

        // Select this folder
        oClient->SelectFolder(oFolder);

        IMailInfoCollectionPtr infos = oClient->GetMailInfoList();
        _tprintf(_T("Total %d emails\r\n"), infos->Count);

        for (long i = 0; i < infos->Count; i++)
        {
            IMailInfoPtr pInfo = infos->GetItem(i);

            TCHAR szFile[MAX_PATH + 1];
            // Generate a random file name by current local datetime,
            // You can use your method to generate the filename if you do not like it
            SYSTEMTIME curtm;
            ::GetLocalTime(&curtm);
            ::wsprintf(szFile, _T("%s\\%04d%02d%02d%02d%02d%02d%03d%d.eml"),
                szMailBox,
                curtm.wYear,
                curtm.wMonth,
                curtm.wDay,
                curtm.wHour,
                curtm.wMinute,
                curtm.wSecond,
                curtm.wMilliseconds,
                i);

            // Receive email from POP3 server
            IMailPtr oMail = oClient->GetMail(pInfo);

            // Save email to local disk
            oMail->SaveAs(szFile, VARIANT_TRUE);

            // Mark email as deleted from POP3 server.
            oClient->Delete(pInfo);
        }

        // Delete method just mark the email as deleted,
        // Quit method expunge the emails from server exactly.
        oClient->Quit();
    }
    catch (_com_error &ep)
    {
        _tprintf(_T("Error: %s"), (const TCHAR*)ep.Description());
    }

    return 0;
}

Next Section

At next section I will introduce how to retrieve email from Exchange Server with WebDAV protocol.

Appendix

Comments

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