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 "eagetmailobj.tlh"
using namespace EAGetMailObjLib;

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

    // 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];
    memset( szPath, 0, sizeof(szPath));
    ::GetModuleFileName( NULL, szPath,  MAX_PATH );

    // Change file name to current full path
    LPCTSTR psz = _tcsrchr( szPath, _T('\\'));
    if( psz != NULL )
    {
        szPath[psz-szPath] = _T('\0');
    }
    TCHAR szMailBox[MAX_PATH+1];
    memset( szMailBox, 0, sizeof(szMailBox));
    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("imap4.emailarchitect.net");
        oServer->User = _T("test@emailarchitect.net");
        oServer->Password = _T("testpassword");
        oServer->Protocol = MailServerImap4;

        // Set IMAP4 port
        oServer->Port = 143;

        // If your IMAP4 server requires SSL connection
        // Please add the following codes
        // oServer->SSLConnection = VARIANT_TRUE;
        // oServer->Port = 993;

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

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

        _variant_t infos = oClient->GetMailInfos();
        SAFEARRAY *psa = infos.parray;
        long LBound = 0, UBound = 0;
        SafeArrayGetLBound( psa, 1, &LBound );
        SafeArrayGetUBound( psa, 1, &UBound );

        INT count = UBound-LBound+1;
        _tprintf(_T("Total %d emails\r\n"), count );

        for( long i = LBound; i <= UBound; i++ )
        {
            _variant_t vtInfo;
            SafeArrayGetElement( psa, &i, &vtInfo );

            IMailInfoPtr pInfo;
            vtInfo.pdispVal->QueryInterface(__uuidof(IMailInfo), (void**)&pInfo);

            TCHAR szFile[MAX_PATH+1];
            memset( szFile, 0, sizeof(szFile));

            // 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 IMAP4 server
            IMailPtr oMail = oClient->GetMail(pInfo);

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

            // Mark email as deleted from IMAP4 server.
            oClient->Delete( pInfo );
        }

        // Delete method just mark the email as deleted,
        // Quit method purge the emails from server exactly.
        infos.Clear();
        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 "eagetmailobj.tlh"
using namespace EAGetMailObjLib;

IImap4FolderPtr
SearchFolder( _variant_t &folders, LPCTSTR lpszFolder )
{
    SAFEARRAY *psa = folders.parray;
    long LBound = 0, UBound = 0;
    SafeArrayGetLBound( psa, 1, &LBound );
    SafeArrayGetUBound( psa, 1, &UBound );
    for( long i = LBound; i <= UBound; i++ )
    {
        _variant_t vt;
        SafeArrayGetElement( psa, &i, &vt );
        IImap4FolderPtr pFolder = NULL;
        vt.pdispVal->QueryInterface( __uuidof(IImap4Folder), (void**)&pFolder);
        _tprintf( _T("Folder: %s\r\n"), (const TCHAR*)pFolder->Name );
        if( _tcsicmp( lpszFolder, (const TCHAR*)pFolder->Name ) == 0 )
        {
            // folder was found
            return pFolder;
        }

        pFolder = SearchFolder( pFolder->SubFolders, lpszFolder );
        if( pFolder != NULL )
        {
            return pFolder;
        }
    }

    // No folder found
    return NULL;
}

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

    // 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];
    memset( szPath, 0, sizeof(szPath));
    ::GetModuleFileName( NULL, szPath,  MAX_PATH );

    // Change file name to current full path
    LPCTSTR psz = _tcsrchr( szPath, _T('\\'));
    if( psz != NULL )
    {
        szPath[psz-szPath] = _T('\0');
    }
    TCHAR szMailBox[MAX_PATH+1];
    memset( szMailBox, 0, sizeof(szMailBox));
    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("imap4.emailarchitect.net");
        oServer->User = _T("test@emailarchitect.net");
        oServer->Password = _T("testpassword");
        oServer->Protocol = MailServerImap4;

        // Set IMAP4 port
        oServer->Port = 143;

        // If your IMAP4 server requires SSL connection
        // Please add the following codes
        // oServer->SSLConnection = VARIANT_TRUE;
        // oServer->Port = 993;

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

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

        // Lookup folder based name.
        _variant_t folders = oClient->Imap4Folders;
        IImap4FolderPtr pFolder = SearchFolder( folders, _T("Deletxed Items"));
        if( pFolder == NULL )
        {
            throw _bstr_t( _T("No folder found"));
        }

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

        _variant_t infos = oClient->GetMailInfos();
        SAFEARRAY *psa = infos.parray;
        long LBound = 0, UBound = 0;
        SafeArrayGetLBound( psa, 1, &LBound );
        SafeArrayGetUBound( psa, 1, &UBound );

        INT count = UBound-LBound+1;
        _tprintf(_T("Total %d emails\r\n"), count );

        for( long i = LBound; i <= UBound; i++ )
        {
            _variant_t vtInfo;
            SafeArrayGetElement( psa, &i, &vtInfo );

            IMailInfoPtr pInfo;
            vtInfo.pdispVal->QueryInterface(__uuidof(IMailInfo), (void**)&pInfo);

            TCHAR szFile[MAX_PATH+1];
            memset( szFile, 0, sizeof(szFile));

            // 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 IMAP4 server
            IMailPtr oMail = oClient->GetMail(pInfo);

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

            // Mark email as deleted from IMAP4 server.
            oClient->Delete( pInfo );
        }

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

    return 0;
}

Next Section

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

Appendix

Comments

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