Parse Email in Visual C++

In previous section, I introduced how to download email with background service. In this section, I will introduce how to parse email in Visual C++.

Introduction

After you received the emails to the local folder, we can use the following code to parse the email now. The following code demonstrates how to parse from, to, cc, subject, body text, attachments of all emails file received by previous sample.

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 - Parse email]

The following example codes demonstrate how to use EAGetMail POP3 component to parse email sender, to, cc, subject, body text and attachments.

Note

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

#include "stdafx.h"

#include "eagetmailobj.tlh"
using namespace EAGetMailObjLib;

void ParseEmail( LPCTSTR lpszFile )
{
    try
    {
        IMailPtr oMail = NULL;
        oMail.CreateInstance(__uuidof(EAGetMailObjLib::Mail));
        oMail->LicenseCode = _T("TryIt");

        oMail->LoadFile( lpszFile, VARIANT_FALSE );

        // Parse email sender
        _tprintf(_T("From: %s\r\n"), (const TCHAR*)oMail->From->Address);

        // Parse to recipient
        _variant_t varry = oMail->To;
        SAFEARRAY *psa = varry.parray;
        long i = 0, LBound = 0, UBound = 0;
        SafeArrayGetLBound( psa, 1, &LBound );
        SafeArrayGetUBound( psa, 1, &UBound );
        for( i = LBound; i <= UBound; i++ )
        {
            _variant_t vt;
            SafeArrayGetElement( psa, &i, &vt );

            IMailAddressPtr pAddr;
            vt.pdispVal->QueryInterface(__uuidof(IMailAddress), (void**)&pAddr);
            _tprintf(_T("To: %s\r\n"), (const TCHAR*)pAddr->Address);
        }

        // Parse CC
        varry = oMail->Cc;
        psa = varry.parray;
        SafeArrayGetLBound( psa, 1, &LBound );
        SafeArrayGetUBound( psa, 1, &UBound );
        for( i = LBound; i <= UBound; i++ )
        {
            _variant_t vt;
            SafeArrayGetElement( psa, &i, &vt );

            IMailAddressPtr pAddr;
            vt.pdispVal->QueryInterface(__uuidof(IMailAddress), (void**)&pAddr);
            _tprintf(_T("Cc: %s\r\n"), (const TCHAR*)pAddr->Address);
        }

        // Parse email subject
        _tprintf(_T("Subject: %s\r\n"), (const TCHAR*)oMail->Subject);

        // Parse email text body
        _tprintf(_T("TextBody: %s\r\n"), (const TCHAR*)oMail->TextBody);

        // Parse email HTML body
        _tprintf(_T("HtmlBody: %s\r\n"), (const TCHAR*)oMail->HtmlBody);

        // Parse attachment
        varry = oMail->Attachments;
        psa = varry.parray;
        SafeArrayGetLBound( psa, 1, &LBound );
        SafeArrayGetUBound( psa, 1, &UBound );
        for( i = LBound; i <= UBound; i++ )
        {
            _variant_t vt;
            SafeArrayGetElement( psa, &i, &vt );

            IAttachmentPtr pAtt;
            vt.pdispVal->QueryInterface(__uuidof(IAttachment), (void**)&pAtt);
            _tprintf(_T("Attachment: %s\r\n"), (const TCHAR*)pAtt->Name);
        }

    }
    catch( _com_error &ep )
    {
        _tprintf(_T("Error: %s\r\n"), (const TCHAR*)ep.Description());
    }
}

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

    // 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
    {
        IToolsPtr oTools = NULL;
        oTools.CreateInstance(__uuidof(EAGetMailObjLib::Tools));
        TCHAR szFind[MAX_PATH+1];
        memset( szFind, 0, sizeof(szFind));
        wsprintf( szFind, _T("%s\\*.eml"), szMailBox );

        // Get all *.eml files in specified folder and parse it one by one.
        _variant_t files = oTools->GetFiles( szFind );
        SAFEARRAY *psa = files.parray;
        long i = 0, LBound = 0, UBound = 0;
        SafeArrayGetLBound( psa, 1, &LBound );
        SafeArrayGetUBound( psa, 1, &UBound );
        for( i = LBound; i <= UBound; i++ )
        {
            _variant_t vt;
            SafeArrayGetElement( psa, &i, &vt );

            ParseEmail(_bstr_t(vt.bstrVal));
        }
    }
    catch( _com_error &ep )
    {
        _tprintf( _T("Error: %s"), (const TCHAR*)ep.Description());
    }

    return 0;
}

TextBody and HtmlBody

Not every email has both text/plain body text and html body text. However, Mail object provides both TextBody and HtmlBody properties smartly. If the email has only text/plain body, then Mail object converts the text/plain body to html body automatically; if the email has only html body, then Mail object converts the html body to text/plain body automatically.

Next Section

At next section I will introduce how to verify digital signature and decrypt email.

Appendix

Comments

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