DataFlex
DataFlex
Processing a multipart/report Delivery Status Notification (Bounce Notification)
See more Email Object Examples
This example discusses the format of Delivery Status Notification emails and how to process them.Chilkat DataFlex Downloads
Use ChilkatAx-win32.pkg
Procedure Test
Boolean iSuccess
Handle hoEmail
Handle hoH2t
Variant vJsonDsnInfo
Handle hoJsonDsnInfo
String sHeadersText
Handle hoMime
Variant vOrigEmail
Handle hoOrigEmail
String sTemp1
Integer iTemp1
Boolean bTemp1
Move False To iSuccess
// Here are the MIME structures, showing the content-type and nesting of the MIME parts of three sample
// multipart/report DSN (Delivery Status Notification) emails.
// This 1st sample includes a "text/rfc822-headers" MIME subpart.
// multipart/report
// text/plain
// message/delivery-status
// text/rfc822-headers
// message/rfc822
// This 2nd sample lacks the text/rfc-headers part, but the "report type" information
// is offered in both plain-text and HTML formats.
// multipart/report
// multipart/alternative
// text/plain
// text/html
// message/delivery-status
// message/rfc822
// ----------------------------------------------------------------------------------------------------
// A multipart/report MIME delivery status notification follows a specific format defined by the Internet Engineering Task Force (IETF) in RFC 3464,
// which outlines the "An Extensible Message Format for Delivery Status Notifications" standard. The format consists of multiple parts within a
// multipart/report structure. Here's an overview of the main parts involved:
//
// The 1st sub-part under multipart/report is the body of the DSN to be displayed by the email client (such as Outlook).
// It can be a simple text/plain body, or it can be multipart/alternative and offer a few alternative format, typically plain-text and HTML.
// HTML is best for viewing a program such as Outlook.
// This part of the multipart/report is not structured for programmatic processing. It's meant to be viewed by a human.
// --------------------
// The "message/delivery-status" part within a multipart/report MIME structure follows a specific format to provide details about the delivery status
// of an email message. Here's an overview of the format and the key components within the "message/delivery-status" part:
//
// (1) Content-Type and Reporting-UA:
// The "message/delivery-status" part begins with the Content-Type header specifying "message/delivery-status".
// It may also include a Reporting-UA (Reporting User Agent) field that identifies the software or system generating the delivery status notification.
//
// For example:
//
// Content-Type: message/delivery-status
// Reporting-UA: Example Mail System 1.0
//
// (2) Fields:
// The "message/delivery-status" part contains a series of fields, each providing specific information about the delivery status.
// These fields are structured as key-value pairs.
//
// Common fields include:
//
// Final-Recipient: Specifies the recipient for whom the delivery status is being reported.
// Action: Describes the action performed by the reporting system (e.g., failed, delivered, delayed, etc.).
// Status: Indicates the status code or reason for the delivery attempt result.
// Remote-MTA: Specifies the host or system that attempted the delivery.
// Diagnostic-Code: Provides additional diagnostic information, such as error codes or explanations.
//
// For example:
//
// Final-Recipient: rfc822; john.doe@example.com
// Action: failed
// Status: 5.1.1
// Remote-MTA: smtp.example.com
// Diagnostic-Code: smtp; 550 Requested action not taken: mailbox unavailable
//
// (3) Additional Fields:
// Additional fields may be included in the "message/delivery-status" part to provide further information about the delivery attempt.
// These fields can vary depending on the implementation or specific needs of the system generating the delivery status notification.
// For example:
//
// X-Spam-Flag: YES
// X-Spam-Score: 7.2
//
// Note: The specific fields and their values within the "message/delivery-status" part can vary depending on the implementation
// or the email server/application generating the delivery status notification. The structure described above represents the standard format
// as defined in RFC 3464, but variations may exist in practice.
// --------------------
// The "text/rfc822-headers" MIME part, if included, contains the headers of the original email message
// for which the delivery status notification is being generated. It provides a subset of the headers from the original message,
// typically excluding the message body and attachments.
//
// The purpose of including the "text/rfc822-headers" part is to provide contextual information about the original message.
// It allows the recipient to review the original headers, such as the subject, sender, recipients, date, and other relevant information,
// in order to understand the context and details of the email message for which the delivery status notification is being generated.
//
// Note that the specific headers included in the "text/rfc822-headers" part can vary based on the implementation or requirements
// of the system generating the delivery status notification.
// --------------------
// If the message/rfc822 part is present, it contains the full MIME of the email that was not delivered.
// In Chilkat terminology, this is an attached message.
// OK, let's write code to process a multipart/report email.
Get Create (RefClass(cComChilkatEmail)) To hoEmail
If (Not(IsComObjectCreated(hoEmail))) Begin
Send CreateComObject of hoEmail
End
Get ComLoadEml Of hoEmail "qa_data/eml/deliveryStatus.eml" To iSuccess
// success = email.LoadEml("qa_data/eml/sample_multipart_report.eml");
If (iSuccess = False) Begin
Get ComLastErrorText Of hoEmail To sTemp1
Showln sTemp1
Procedure_Return
End
// Verify this is a multipart/report email..
Get ComIsMultipartReport Of hoEmail To bTemp1
If (bTemp1 = False) Begin
Showln "Not a multipart/report email."
Procedure_Return
End
// Get the body that is to be displayed to a human in an email program (such as Outlook).
Get ComHasPlainTextBody Of hoEmail To bTemp1
If (bTemp1 = True) Begin
Showln "Plain text body:"
// println email.GetPlainTextBody();
End
Else Begin
Get ComHasHtmlBody Of hoEmail To bTemp1
If (bTemp1 = True) Begin
// Convert HTML to plain-text..
Get Create (RefClass(cComChilkatHtmlToText)) To hoH2t
If (Not(IsComObjectCreated(hoH2t))) Begin
Send CreateComObject of hoH2t
End
Showln "HTML body converted to plain-text:"
Get ComToText Of hoH2t (ComGetHtmlBody(hoEmail)) To sTemp1
Showln sTemp1
End
Else Begin
Showln "Has no plain-text or HTML body..."
End
End
Showln "---------------------------------"
// Now get information from the message/delivery-status part (or the message/disposition-notification part)
Showln "--- Delivery Status Information:"
Get ComGetDeliveryStatusInfo Of hoEmail "Status" To sTemp1
Showln "Status: " sTemp1
Get ComGetDeliveryStatusInfo Of hoEmail "Action" To sTemp1
Showln "Action: " sTemp1
Get ComGetDeliveryStatusInfo Of hoEmail "Reporting-MTA" To sTemp1
Showln "Reporting-MTA: " sTemp1
Get Create (RefClass(cComChilkatJsonObject)) To hoJsonDsnInfo
If (Not(IsComObjectCreated(hoJsonDsnInfo))) Begin
Send CreateComObject of hoJsonDsnInfo
End
Get pvComObject of hoJsonDsnInfo to vJsonDsnInfo
Get ComGetDsnInfo Of hoEmail vJsonDsnInfo To iSuccess
Set ComEmitCompact Of hoJsonDsnInfo To False
Get ComEmit Of hoJsonDsnInfo To sTemp1
Showln sTemp1
Showln "---------------------------------"
// If the multipart/report contains a text/rfc822-headers, it can be retrieved like this:
Get ComGetNthTextPartOfType Of hoEmail 0 "text/rfc822-headers" False False To sHeadersText
Get ComLastMethodSuccess Of hoEmail To bTemp1
If (bTemp1 = True) Begin
Showln "The text/rfc822-headers part exists.."
Showln ""
Showln sHeadersText
// If you wish to process the headers, you can load them into a MIME object and use the Chilkat MIME functionality to examine the headers.
Get Create (RefClass(cComChilkatMime)) To hoMime
If (Not(IsComObjectCreated(hoMime))) Begin
Send CreateComObject of hoMime
End
Get ComLoadMime Of hoMime sHeadersText To iSuccess
// Do whatever you want..
// For example, look at the "To" header.
Showln "MIME To header:"
Get ComGetHeaderField Of hoMime "To" To sTemp1
Showln sTemp1
End
Showln "---------------------------------"
// Finally, if the original email was attached, you can load it into another Chilkat Email object instance and
// do what you want with it..
Get ComNumAttachedMessages Of hoEmail To iTemp1
If (iTemp1 > 0) Begin
// Get the 1st attachment message (assume we don't have more than one attached message)
Get Create (RefClass(cComChilkatEmail)) To hoOrigEmail
If (Not(IsComObjectCreated(hoOrigEmail))) Begin
Send CreateComObject of hoOrigEmail
End
Get pvComObject of hoOrigEmail to vOrigEmail
Get ComGetAttachedEmail Of hoEmail 0 vOrigEmail To iSuccess
If (iSuccess = True) Begin
Get ComSubject Of hoOrigEmail To sTemp1
Showln "Attached message subject: " sTemp1
// Do whatever else you want..
End
End
End_Procedure