Visual C++ - Convert email to HTML¶

#include "stdafx.h"
#include <windows.h>
#include <atlstr.h>

#include "eagetmailobj.tlh"
using namespace EAGetMailObjLib;

CString _FormatHtmlTag(LPCTSTR lpszSrc)
{
    CString src = lpszSrc;

    src.Replace(_T(">"), _T("&gt;"));
    src.Replace(_T("<"), _T("&lt;"));
    return src;
}

// we parse the email file and generate a html + attachment folder for the email, once the html is create,
// you can open this html with IE and view the content and get the attachments.
void
ParseEmailToHtml(CString &emlFile)
{
    try
    {
        int pos = emlFile.ReverseFind(_T('.'));
        CString htmlFile = emlFile.Mid(0, pos) + _T(".htm");
        CString attachmentFolder = emlFile.Mid(0, pos);

        IMailPtr oMail;
        oMail.CreateInstance(__uuidof(EAGetMailObjLib::Mail));
        oMail->LicenseCode = _T("TryIt");

        oMail->LoadFile(emlFile.GetString(), VARIANT_FALSE);

        if (oMail->IsEncrypted == VARIANT_TRUE)
        {
            try
            {
                //this email is encrypted, we decrypt it by user default certificate.
                // you can also use specified certificate like this
                // oCert = new Certificate();
                // oCert.Load("c:\\test.pfx", "pfxpassword", Certificate.CertificateKeyLocation.CRYPT_USER_KEYSET)
                // oMail = oMail.Decrypt( oCert );
                oMail = oMail->Decrypt(NULL);
            }
            catch (_com_error &ep)
            {
                _tprintf(_T("%s\r\n"), (TCHAR*)ep.Description());
                oMail->LoadFile(emlFile.GetString(), VARIANT_FALSE);
            }
        }

        if (oMail->IsSigned == VARIANT_TRUE)
        {
            try
            {
                //this email is digital signed.
                ICertificatePtr oCert = oMail->VerifySignature();
                _tprintf(_T("This email contains a valid digital signature.\r\n"));
                //you can add the certificate to your certificate storage like this
                //cert.AddToStore( Certificate.CertificateStoreLocation.CERT_SYSTEM_STORE_CURRENT_USER,
                //  "addressbook" );
                // then you can use send the encrypted email back to this sender.
            }
            catch (_com_error &ep)
            {
                _tprintf(_T("%s\r\n"), (TCHAR*)ep.Description());
            }
        }

        // Decode winmail.dat (TNEF) automatically'
        // also convert RTF body to HTML body automatically
        oMail->DecodeTNEF();

        CString html = (TCHAR*)oMail->HtmlBody;

        CString header;
        header.Preallocate(1024 * 5);

        header.Append(_T("<font face=\"Courier New,Arial\" size=2>"));
        header.Append(_T("<b>From:</b> "));

        CString tempValue = (TCHAR*)oMail->From->Name;
        tempValue += _T("<");
        tempValue += (TCHAR*)oMail->From->Address;
        tempValue += _T(">");
        header.Append(_FormatHtmlTag(tempValue.GetString()));
        header.Append(_T("<br>"));

        IAddressCollectionPtr addressList = oMail->ToList;
        if (addressList->Count > 0)
        {
            header.Append(_T("<b>To:</b> "));
            for (long i = 0; i < addressList->Count; i++)
            {
                IMailAddressPtr pAddr = addressList->GetItem(i);

                tempValue = (TCHAR*)pAddr->Name;
                tempValue += _T("<");
                tempValue += (TCHAR*)pAddr->Address;
                tempValue += _T(">");

                header.Append(_FormatHtmlTag(tempValue.GetString()));
                header.Append(_T(";"));
            }
            header.Append(_T("<br>"));
        }

        addressList->Clear();
        addressList = oMail->CcList;

        if (addressList->Count > 0)
        {
            header.Append(_T("<b>Cc:</b> "));
            for (long i = 0; i < addressList->Count; i++)
            {
                IMailAddressPtr pAddr = addressList->GetItem(i);

                tempValue = (TCHAR*)pAddr->Name;
                tempValue += _T("<");
                tempValue += (TCHAR*)pAddr->Address;
                tempValue += _T(">");

                header.Append(_FormatHtmlTag(tempValue.GetString()));
                header.Append(_T(";"));
            }
            header.Append(_T("<br>"));
        }

        header.Append(_T("<b>Subject:</b>"));
        header.Append(_FormatHtmlTag((TCHAR*)oMail->Subject));
        header.Append(_T("<br>"));

        IAttachmentCollectionPtr attList = oMail->AttachmentList;
        if (attList->Count > 0)
        {
            ::CreateDirectory(attachmentFolder.GetString(), NULL);
            header.Append(_T("<b>Attachments:</b>"));

            for (long i = 0; i < attList->Count; i++)
            {
                IAttachmentPtr pAtt = attList->GetItem(i);

                CString name = (TCHAR*)pAtt->Name;

                CString attName = attachmentFolder;
                attName.Append(_T("\\"));
                attName.Append((TCHAR*)pAtt->Name);
                pAtt->SaveAs(attName.GetString(), VARIANT_TRUE);

                header.Append(_T("<a href=\""));
                header.Append(attName);
                header.Append(_T("\" target=\"_blank\">"));
                header.Append((TCHAR*)pAtt->Name);
                header.Append(_T("</a> "));

                CString contentID = (TCHAR*)pAtt->ContentID;
                CString contentType = (TCHAR*)pAtt->ContentType;
                if (contentID.GetLength() > 0)
                {
                    CString find = _T("cid:");
                    find.Append(contentID);
                    //show embedded image.
                    html.Replace(find, attName);
                }
                else if (_tcsnicmp(contentType.GetString(), _T("image/"), _tcslen(_T("image/"))) == 0)
                {
                    //show attached image
                    html.Append(_T("<hr><img src=\""));
                    html.Append(attName);
                    html.Append(_T("\">"));
                }
            }
        }

        header.Insert(0, _T("<meta HTTP-EQUIV=\"Content-Type\" Content=\"text-html; charset=utf-8\">"));

        html = header + "<hr>" + html;

        IToolsPtr oTools;
        oTools.CreateInstance(__uuidof(EAGetMailObjLib::Tools));
        oTools->WriteTextFile(htmlFile.GetString(), html.GetString(), CP_UTF8);
    }
    catch (_com_error &exp)
    {
        _tprintf(_T("%s\r\n"), (TCHAR*)exp.Description());
    }
}

int _tmain(int argc, _TCHAR* argv[])
{
    // Initialize COM environment
    ::CoInitialize(NULL);

    CString emlFile = _T("c:\\my folder\\test.eml");
    ParseEmailToHtml(emlFile);
    return 0;
}