Retrieve Email from IMAP4 server in Visual C++

In previous section, I introduced retrieving email from POP3 server in Visual C++. In this section, I will introduce the IMAP4 server.

Introduction

IMAP4 protocol is different with POP3 protocol. First of all, IMAP4 supports retrieving email from different mail folder and folder management. Secondly, IMAP4 supports mail flags management. Therefore, we can do more things with IMAP4 server. To better understand the IMAP4 protocol, please see the following examples.

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 IMAP4 inbox]

The following example codes demonstrate how to download email from IMAP4 server default mailbox. 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));

        oServer->Server = _T("pop3.emailarchitect.net");
        oServer->User = _T("test@emailarchitect.net");
        oServer->Password = _T("testpassword");
        oServer->Protocol = MailServerImap4;

        // Enable SSL Connection, most modern email servers require SSL/TLS by default
        oServer->SSLConnection = VARIANT_TRUE;
        oServer->Port = 993;

        // If your IMAP doesn't deploy SSL connection
        // Please use
        // oServer->SSLConnection = VARIANT_FALSE;
        // oServer->Port = 143;

        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 IMAP4 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 IMAP4 account. 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;

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));

        oServer->Server = _T("pop3.emailarchitect.net");
        oServer->User = _T("test@emailarchitect.net");
        oServer->Password = _T("testpassword");
        oServer->Protocol = MailServerImap4;

        // Enable SSL Connection, most modern email servers require SSL/TLS by default
        oServer->SSLConnection = VARIANT_TRUE;
        oServer->Port = 993;

        // If your IMAP doesn't deploy SSL connection
        // Please use
        // oServer->SSLConnection = VARIANT_FALSE;
        // oServer->Port = 143;

        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;
}

TLS 1.2

TLS is the successor of SSL, more and more Email servers require TLS 1.2 encryption now.

If your operating system is Windows XP/Vista/Windows 7/Windows 2003/2008/2008 R2/2012/2012 R2, and you got connection error with SSL/TLS connection, you need to enable TLS 1.2 protocol in your operating system like this:

Enable TLS 1.2 on Windows XP/Vista/7/10/Windows 2008/2008 R2/2012

Next Section

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

Appendix

Comments

If you have any comments or questions about above example codes, please click here to add your comments.