JMAP R. Ouazana, Ed.
Internet-Draft Linagora
Intended status: Standards Track July 27, 2020
Expires: January 28, 2021

Handling Message Disposition Notification with JMAP
draft-ietf-jmap-mdn-15

Abstract

This document specifies a data model for handling Message Disposition Notifications (MDNs, RFC 8098) in the JSON Meta Application Protocol (JMAP, RFCs 8620 and 8621).

Status of This Memo

This Internet-Draft is submitted in full conformance with the provisions of BCP 78 and BCP 79.

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Table of Contents

1. Introduction

JMAP ([RFC8620] – JSON Meta Application Protocol) is a generic protocol for synchronising data, such as mail, calendars or contacts, between a client and a server. It is optimised for mobile and web environments, and provides a consistent interface to different data types.

JMAP for Mail ([RFC8621] - The JSON Meta Application Protocol (JMAP) for Mail) specifies a data model for synchronising email data with a server using JMAP. Clients can use this to efficiently search, access, organise, and send messages.

Message Disposition Notifications (MDNs) are defined in [RFC8098] and are used as "read receipts", "acknowledgements", or "receipt notifications".

A client can have to deal with MDNs in different ways:

  1. When receiving an email message, an MDN can be sent to the sender. This specification defines an MDN/send method to cover this case.
  2. When sending an email message, an MDN can be requested. This must be done with the help of a header, and is already specified by [RFC8098] and can already be handled by [RFC8621] this way.
  3. When receiving an MDN, the MDN could be related to an existing sent message. This is already covered by [RFC8621] in the EmailSubmission object. A client might want to display detailed information about a received MDN. This specification defines an MDN/parse method to cover this case.

1.1. Notational conventions

The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in BCP 14 [RFC2119] [RFC8174] when, and only when, they appear in all capitals, as shown here.

Type signatures, examples and property descriptions in this document follow the conventions established in section 1.1 of [RFC8620]. Data types defined in the core specification are also used in this document.

Servers MUST support all properties specified for the new data types defined in this document.

1.2. Terminology

The same terminology is used in this document as in the core JMAP specification.

Because keywords are case-insensitive in IMAP but case-sensitive in JMAP, the "$mdnsent" keyword MUST always be used in lowercase.

1.3. Addition to the capabilities object

Capabilities are announced as part of the standard JMAP Session resource; see [RFC8620], section 2. This defines a new capability, "urn:ietf:params:jmap:mdn".

The capability "urn:ietf:params:jmap:mdn" being present in the "accountCapabilities" property of an account represents support for the "MDN" data type, parsing MDNs via the "MDN/parse" method, and creating and sending MDN messages via the "MDN/send" method. Servers that include the capability in one or more "accountCapabilities" properties MUST also include the property in the "capabilities" property.

The value of this "urn:ietf:params:jmap:mdn" property is an empty object in the account's "accountCapabilities" property.

2. MDN

An MDN object has the following properties:

A Disposition object has the following properties:

See [RFC8098] for the exact meaning of these different fields. These fields are defined case insensitive in [RFC8098] but are case sensitive in this RFC and MUST be converted to lowercase by "MDN/parse".

2.1. MDN/send

The MDN/send method sends an [RFC5322] message from an MDN object. When calling this method the "using" property of the Request object MUST contain the capabilities "urn:ietf:params:jmap:mdn" and "urn:ietf:params:jmap:mail". The latter because of the implicit call to Email/set and the use of Identities, described below. The method takes the following arguments:

The response has the following arguments:

The following already registered SetError would mean:

The following is a new SetError:

If the accountId or identityId given cannot be found, the method call is rejected with an invalidArguments error.

The client MUST NOT issue an MDN/send request if the message has the $mdnsent keyword set.

When sending the MDN, the server is in charge of generating the "originalRecipient", "finalRecipient" and "originalMessageId" fields according to the [RFC8098] specification.

The client is expected to explicitly update each "Email" for which an "MDN/send" has been invoked in order to set the "$mdnsent" keyword on these messages. To ensure that, the server MUST reject an "MDN/send" which does not result in setting the keyword "$mdnsent". Thus the server MUST check that the "onSuccessUpdateEmail" property of the method is correctly set to update this keyword.

2.2. MDN/parse

This method allows a client to parse blobs as [RFC5322] messages to get MDN objects. This can be used to parse and get detailed information about blobs referenced in the "mdnBlobIds" of the EmailSubmission object, or any email message the client could expect to be an MDN.

The "forEmailId" property can be null or missing if the "originalMessageId" property is missing or does not refer to an existing message, or if the server cannot efficiently calculate the related message (for example, if several messages get the same "Message-Id" header).

The MDN/parse method takes the following arguments:

The response has the following arguments:

The following additional errors may be returned instead of the MDN/parse response:

3. Samples

3.1. Sending an MDN for a received email message

A client can use the following request to send an MDN back to the sender:

[[ "MDN/send", {
  "accountId": "ue150411c",
  "identityId": "I64588216",
  "send": {
    "k1546": {
      "forEmailId": "Md45b47b4877521042cec0938",
      "subject": "Read receipt for: World domination",
      "textBody": "This receipt shows that the email has been 
          displayed on your recipient's computer. There is no 
          guaranty it has been read or understood.",
      "reportingUA": "joes-pc.cs.example.com; Foomail 97.1",
      "disposition": {
        "actionMode": "manual-action",
        "sendingMode": "mdn-sent-manually",
        "type": "displayed"
      },
      "extension": {
        "X-EXTENSION-EXAMPLE": "example.com"
      }
    }
  },
  "onSuccessUpdateEmail": {
    "#k1546": {
      "keywords/$mdnsent": true
    }
  }
}, "0" ]]

If the email id matches an existing email message without the $mdnsent keyword, the server can answer:

[[ "MDN/send", {
  "accountId": "ue150411c",
  "sent": {
    "k1546": {
      "finalRecipient": "rfc822; john@example.com",
      "originalMessageId": "<199509192301.23456@example.org>"
    }
  }
}, "0" ],
[ "Email/set", {
  "accountId": "ue150411c",
  "oldState": "23",
  "newState": "42",
  "updated": {
    "Md45b47b4877521042cec0938": {}
  }
}, "0" ]]

If the $mdnsent keyword has already been set, the server can answer an error:

[[ "MDN/send", {
  "accountId": "ue150411c",
  "notSent": {
    "k1546": {
      "type": "mdnAlreadySent",
      "description" : "$mdnsent keyword is already present"
    }
  }
}, "0" ]]

3.2. Asking for MDN when sending an email message

This is done with the [RFC8621] "Email/set" "create" method.

[[ "Email/set", {
  "accountId": "ue150411c",
  "create": {
    "k1546": {
      "mailboxIds": {
        "2ea1ca41b38e": true
      },
      "keywords": {
        "$seen": true,
        "$draft": true
      },
      "from": [{
        "name": "Joe Bloggs",
        "email": "joe@example.com"
      }],
      "to": [{
        "name": "John",
        "email": "john@example.com"
      }],
      "header:Disposition-Notification-To:asText": "joe@example.com",
      "subject": "World domination",
      ...
    }
  }
}, "0" ]]

Note the specified Disposition-Notification-To header indicating where to send MDN back (usually the sender of the message).

3.3. Parsing a received MDN

The client issues a parse request:

[[ "MDN/parse", {
  "accountId": "ue150411c",
  "blobIds": [ "0f9f65ab-dc7b-4146-850f-6e4881093965" ]
}, "0" ]]

The server responds:

[[ "MDN/parse", {
  "accountId": "ue150411c",
  "parsed": {
    "0f9f65ab-dc7b-4146-850f-6e4881093965": {
      "forEmailId": "Md45b47b4877521042cec0938",
      "subject": "Read receipt for: World domination",
      "textBody": "This receipt shows that the email has been 
          displayed on your recipient's computer. There is no 
          guaranty it has been read or understood.",
      "reportingUA": "joes-pc.cs.example.com; Foomail 97.1",
      "disposition": {
        "actionMode": "manual-action",
        "sendingMode": "mdn-sent-manually",
        "type": "displayed"
      },
      "finalRecipient": "rfc822; john@example.com",
      "originalMessageId": "<199509192301.23456@example.org>"
    }
  }
}, "0" ]]

In case of a not found blobId, the server would respond:

[[ "MDN/parse", {
  "accountId": "ue150411c",
  "notFound": [ "0f9f65ab-dc7b-4146-850f-6e4881093965" ]
}, "0" ]]

If the blobId has been found but is not parsable, the server would respond:

[[ "MDN/parse", {
  "accountId": "ue150411c",
  "notParsable": [ "0f9f65ab-dc7b-4146-850f-6e4881093965" ]
}, "0" ]]

4. IANA Considerations

4.1. JMAP Capability Registration for "mdn"

IANA will register the "mdn" JMAP Capability as follows:

Capability Name: urn:ietf:params:jmap:mdn

Specification document: this document

Intended use: common

Change Controller: IETF

Security and privacy considerations: this document, section 5.

4.2. JMAP Error Codes Registry

This section registers one new error code in the "JMAP Error Codes" registry, as defined in [RFC8620].

JMAP Error Code: mdnAlreadySent

Intended use: common

Change controller: IETF

Reference: This document, Section 2.1

Description: The message has the $mdnsent keyword already set. The client MUST NOT try again to send an MDN for this message.

5. Security considerations

The same considerations regarding MDN (see [RFC8098] and [RFC3503]) apply to this document.

In order to enforce trust regarding the relation between the user sending an email message and the identity of this user, the server SHOULD validate in conformance to the provided Identity that the user is permitted to use the finalRecipient value and return a forbiddenFrom error if not.

6. Normative References

[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, DOI 10.17487/RFC2119, March 1997.
[RFC3503] Melnikov, A., "Message Disposition Notification (MDN) profile for Internet Message Access Protocol (IMAP)", RFC 3503, DOI 10.17487/RFC3503, March 2003.
[RFC5322] Resnick, P., "Internet Message Format", RFC 5322, DOI 10.17487/RFC5322, October 2008.
[RFC8098] Hansen, T. and A. Melnikov, "Message Disposition Notification", STD 85, RFC 8098, DOI 10.17487/RFC8098, February 2017.
[RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC 2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174, May 2017.
[RFC8620] Jenkins, N. and C. Newman, "The JSON Meta Application Protocol (JMAP)", RFC 8620, DOI 10.17487/RFC8620, July 2019.
[RFC8621] Jenkins, N. and C. Newman, "The JSON Meta Application Protocol (JMAP) for Mail", RFC 8621, DOI 10.17487/RFC8621, August 2019.

Author's Address

Raphaël Ouazana (editor) Linagora 100 Terrasse Boieldieu – Tour Franklin Paris - La Défense CEDEX, 92042 France EMail: rouazana@linagora.com URI: https://www.linagora.com