(C++) Load .eml and Examine the Structure, Attachments, and Related Items

Demonstrates how to load examine the MIME structure of a .eml, and also examine the attachment and related item filenames, attached messages, and multipart/report and DSN information.

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#include <CkMime.h>
#include <CkEmail.h>
#include <CkStringArray.h>

void ChilkatSample(void)
    {
    // This example requires the Chilkat API to have been previously unlocked.
    // See Global Unlock Sample for sample code.

    const char *emlPath = "C:/AAWorkarea/beatrix/roesner.eml";

    CkMime mime;

    bool success = mime.LoadMimeFile(emlPath);
    if (success != true) {
        std::cout << mime.lastErrorText() << "\r\n";
        return;
    }

    std::cout << "---- MIME structure ----" << "\r\n";
    std::cout << mime.getStructure("text") << "\r\n";
    std::cout << "------------------------" << "\r\n";

    CkEmail email;
    success = email.LoadEml(emlPath);

    // Was this a signed and/or encrypted email?
    // If so, then loading the .eml automatically unwraps
    // (i.e. verifies signatures and decrypts) and the resultant
    // email is what existed prior to signing/encrypting.
    std::cout << "Email was Signed: " << email.get_ReceivedSigned() << "\r\n";
    std::cout << "Email was Encrypted: " << email.get_ReceivedEncrypted() << "\r\n";
    if (email.get_ReceivedSigned() == true) {
        std::cout << "Signature(s) valid = " << email.get_SignaturesValid() << "\r\n";
    }

    if (email.get_ReceivedEncrypted() == true) {
        std::cout << "Decrypted successfully = " << email.get_Decrypted() << "\r\n";
    }

    int i = 0;
    int numAttach = email.get_NumAttachments();
    std::cout << "Number of attachments = " << numAttach << "\r\n";

    while (i < numAttach) {
        std::cout << "---- Attachment " << i << "\r\n";

        // Examine the filename (if any)
        std::cout << "filename: " << email.getAttachmentFilename(i) << "\r\n";
        // Examine the content-ID (if any)
        std::cout << "Content-ID: " << email.getAttachmentContentID(i) << "\r\n";
        // Examine the content-type
        std::cout << "Content-Type: " << email.getAttachmentContentType(i) << "\r\n";
        // Examine the content-disposition
        std::cout << "Content-Disposition" << email.getAttachmentHeader(i,"content-disposition") << "\r\n";
        // Examine the attachment size:
        std::cout << "Size (in bytes) of the attachment: " << email.GetAttachmentSize(i) << "\r\n";

        i = i + 1;
    }

    std::cout << "--" << "\r\n";

    // Now for the related items.

    // Note: A MIME sub-part can potentially be both a related item AND an attachment.
    // The typical case is when the item is contained under the multipart/related enclosure and 
    // the item also has a "Content-Disposition" header indicating "attachment".
    // The location within multipart/related makes it a "related item", yet the Content-Disposition can also make it semantically an attachment.
    // Related items and attachments are not necessarily mutually exclusive.

    int numRelated = email.get_NumRelatedItems();
    std::cout << "Number of related items = " << numRelated << "\r\n";
    i = 0;
    while (i < numRelated) {
        std::cout << "---- Related Item " << i << "\r\n";

        // Examine the filename (if any)
        std::cout << "filename: " << email.getRelatedFilename(i) << "\r\n";
        // Examine the content-ID (if any)
        std::cout << "Content-ID: " << email.getRelatedContentID(i) << "\r\n";
        // Examine the content-type
        std::cout << "Content-Type: " << email.getRelatedContentType(i) << "\r\n";
        // Examine the content-location (if any)
        std::cout << "Content-Location" << email.getRelatedContentLocation(i) << "\r\n";

        i = i + 1;
    }

    // The email could also have attached messages.
    // An attached message is another email that was attached to this email.
    int numAttachedMessages = email.get_NumAttachedMessages();
    std::cout << "Number of attached messages = " << numAttachedMessages << "\r\n";
    i = 0;
    while (i < numAttachedMessages) {
        std::cout << "---- Attached message " << i << "\r\n";

        // Examine the attached email
        CkEmail *em = email.GetAttachedMessage(i);
        std::cout << "from: " << em->ck_from() << "\r\n";
        std::cout << "subject: " << em->subject() << "\r\n";
        delete em;
        i = i + 1;
    }

    // An email could also be a multipart/report email. 
    // This is a DSN (Delivery Status Notification)
    // The NumReports property indicates how many "reports" exist.
    int numReports = email.get_NumReports();
    i = 0;
    std::cout << "Number of reports = " << numReports << "\r\n";
    i = 0;
    while (i < numReports) {
        std::cout << "---- Report " << i << "\r\n";
        // Get the raw report data...
        std::cout << email.getReport(i) << "\r\n";
        i = i + 1;
    }

    // If the email is a multipart/report, then the information
    // from the message/delivery-status part of the email can be retrieved:
    if (email.IsMultipartReport() == true) {

        std::cout << "--- Delivery Status Information:" << "\r\n";
        std::cout << "Status: " << email.getDeliveryStatusInfo("Status") << "\r\n";
        std::cout << "Action: " << email.getDeliveryStatusInfo("Action") << "\r\n";
        std::cout << "Reporting-MTA: " << email.getDeliveryStatusInfo("Reporting-MTA") << "\r\n";

        CkStringArray *sa = email.GetDsnFinalRecipients();
        int numFinalRecipients = sa->get_Count();
        i = 0;
        while (i < numFinalRecipients) {
            std::cout << "final recipient: " << sa->getString(i) << "\r\n";
            i = i + 1;
        }

        delete sa;
    }
    }