(.NET Core 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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// This example requires the Chilkat API to have been previously unlocked.
// See Global Unlock Sample for sample code.

string emlPath = "C:/AAWorkarea/beatrix/roesner.eml";

Chilkat.Mime mime = new Chilkat.Mime();

bool success = mime.LoadMimeFile(emlPath);
if (success != true) {
    Debug.WriteLine(mime.LastErrorText);
    return;
}

Debug.WriteLine("---- MIME structure ----");
Debug.WriteLine(mime.GetStructure("text"));
Debug.WriteLine("------------------------");

Chilkat.Email email = new Chilkat.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.
Debug.WriteLine("Email was Signed: " + Convert.ToString(email.ReceivedSigned));
Debug.WriteLine("Email was Encrypted: " + Convert.ToString(email.ReceivedEncrypted));
if (email.ReceivedSigned == true) {
    Debug.WriteLine("Signature(s) valid = " + Convert.ToString(email.SignaturesValid));
}

if (email.ReceivedEncrypted == true) {
    Debug.WriteLine("Decrypted successfully = " + Convert.ToString(email.Decrypted));
}

int i = 0;
int numAttach = email.NumAttachments;
Debug.WriteLine("Number of attachments = " + Convert.ToString(numAttach));

while (i < numAttach) {
    Debug.WriteLine("---- Attachment " + Convert.ToString(i));

    // Examine the filename (if any)
    Debug.WriteLine("filename: " + email.GetAttachmentFilename(i));
    // Examine the content-ID (if any)
    Debug.WriteLine("Content-ID: " + email.GetAttachmentContentID(i));
    // Examine the content-type
    Debug.WriteLine("Content-Type: " + email.GetAttachmentContentType(i));
    // Examine the content-disposition
    Debug.WriteLine("Content-Disposition" + email.GetAttachmentHeader(i,"content-disposition"));
    // Examine the attachment size:
    Debug.WriteLine("Size (in bytes) of the attachment: " + Convert.ToString(email.GetAttachmentSize(i)));

    i = i + 1;
}

Debug.WriteLine("--");

// 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.NumRelatedItems;
Debug.WriteLine("Number of related items = " + Convert.ToString(numRelated));
i = 0;
while (i < numRelated) {
    Debug.WriteLine("---- Related Item " + Convert.ToString(i));

    // Examine the filename (if any)
    Debug.WriteLine("filename: " + email.GetRelatedFilename(i));
    // Examine the content-ID (if any)
    Debug.WriteLine("Content-ID: " + email.GetRelatedContentID(i));
    // Examine the content-type
    Debug.WriteLine("Content-Type: " + email.GetRelatedContentType(i));
    // Examine the content-location (if any)
    Debug.WriteLine("Content-Location" + email.GetRelatedContentLocation(i));

    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.NumAttachedMessages;
Debug.WriteLine("Number of attached messages = " + Convert.ToString(numAttachedMessages));
i = 0;
while (i < numAttachedMessages) {
    Debug.WriteLine("---- Attached message " + Convert.ToString(i));

    // Examine the attached email
    Chilkat.Email em = email.GetAttachedMessage(i);
    Debug.WriteLine("from: " + em.From);
    Debug.WriteLine("subject: " + em.Subject);

    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.NumReports;
i = 0;
Debug.WriteLine("Number of reports = " + Convert.ToString(numReports));
i = 0;
while (i < numReports) {
    Debug.WriteLine("---- Report " + Convert.ToString(i));
    // Get the raw report data...
    Debug.WriteLine(email.GetReport(i));
    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) {

    Debug.WriteLine("--- Delivery Status Information:");
    Debug.WriteLine("Status: " + email.GetDeliveryStatusInfo("Status"));
    Debug.WriteLine("Action: " + email.GetDeliveryStatusInfo("Action"));
    Debug.WriteLine("Reporting-MTA: " + email.GetDeliveryStatusInfo("Reporting-MTA"));

    Chilkat.StringArray sa = email.GetDsnFinalRecipients();
    int numFinalRecipients = sa.Count;
    i = 0;
    while (i < numFinalRecipients) {
        Debug.WriteLine("final recipient: " + sa.GetString(i));
        i = i + 1;
    }

}