(Go) 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.

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

    mime := chilkat.NewMime()

    success := mime.LoadMimeFile(emlPath)
    if success != true {
        fmt.Println(mime.LastErrorText())
        mime.DisposeMime()
        return
    }

    fmt.Println("---- MIME structure ----")
    fmt.Println(*mime.GetStructure("text"))
    fmt.Println("------------------------")

    email := chilkat.NewEmail()
    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.
    fmt.Println("Email was Signed: ", email.ReceivedSigned())
    fmt.Println("Email was Encrypted: ", email.ReceivedEncrypted())
    if email.ReceivedSigned() == true {
        fmt.Println("Signature(s) valid = ", email.SignaturesValid())
    }

    if email.ReceivedEncrypted() == true {
        fmt.Println("Decrypted successfully = ", email.Decrypted())
    }

    i := 0
    numAttach := email.NumAttachments()
    fmt.Println("Number of attachments = ", numAttach)

    for i < numAttach {
        fmt.Println("---- Attachment ", i)

        // Examine the filename (if any)
        fmt.Println("filename: ", *email.GetAttachmentFilename(i))
        // Examine the content-ID (if any)
        fmt.Println("Content-ID: ", *email.GetAttachmentContentID(i))
        // Examine the content-type
        fmt.Println("Content-Type: ", *email.GetAttachmentContentType(i))
        // Examine the content-disposition
        fmt.Println("Content-Disposition", *email.GetAttachmentHeader(i,"content-disposition"))
        // Examine the attachment size:
        fmt.Println("Size (in bytes) of the attachment: ", *email.GetAttachmentSize(i))

        i = i + 1
    }

    fmt.Println("--")

    // 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.

    numRelated := email.NumRelatedItems()
    fmt.Println("Number of related items = ", numRelated)
    i = 0
    for i < numRelated {
        fmt.Println("---- Related Item ", i)

        // Examine the filename (if any)
        fmt.Println("filename: ", *email.GetRelatedFilename(i))
        // Examine the content-ID (if any)
        fmt.Println("Content-ID: ", *email.GetRelatedContentID(i))
        // Examine the content-type
        fmt.Println("Content-Type: ", *email.GetRelatedContentType(i))
        // Examine the content-location (if any)
        fmt.Println("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.
    numAttachedMessages := email.NumAttachedMessages()
    fmt.Println("Number of attached messages = ", numAttachedMessages)
    i = 0
    for i < numAttachedMessages {
        fmt.Println("---- Attached message ", i)

        // Examine the attached email
        em := email.GetAttachedMessage(i)
        fmt.Println("from: ", em.From())
        fmt.Println("subject: ", em.Subject())
        em.DisposeEmail()
        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.
    numReports := email.NumReports()
    i = 0
    fmt.Println("Number of reports = ", numReports)
    i = 0
    for i < numReports {
        fmt.Println("---- Report ", i)
        // Get the raw report data...
        fmt.Println(*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 {

        fmt.Println("--- Delivery Status Information:")
        fmt.Println("Status: ", *email.GetDeliveryStatusInfo("Status"))
        fmt.Println("Action: ", *email.GetDeliveryStatusInfo("Action"))
        fmt.Println("Reporting-MTA: ", *email.GetDeliveryStatusInfo("Reporting-MTA"))

        sa := email.GetDsnFinalRecipients()
        numFinalRecipients := sa.Count()
        i = 0
        for i < numFinalRecipients {
            fmt.Println("final recipient: ", *sa.GetString(i))
            i = i + 1
        }

        sa.DisposeStringArray()
    }


    mime.DisposeMime()
    email.DisposeEmail()