Internet DRAFT - draft-happel-sml-structured-vacation-notices
draft-happel-sml-structured-vacation-notices
SML H.-J. Happel
Internet-Draft audriga GmbH
Intended status: Standards Track 4 March 2024
Expires: 5 September 2024
Structured vacation notices
draft-happel-sml-structured-vacation-notices-00
Abstract
This document describes a machine-readable format for vacation notice
messages. It is supposed to be used in conjuction with conventional,
human-readable vacation notices.
Status of This Memo
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Copyright Notice
Copyright (c) 2024 IETF Trust and the persons identified as the
document authors. All rights reserved.
This document is subject to BCP 78 and the IETF Trust's Legal
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Please review these documents carefully, as they describe your rights
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Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
2. Conventions Used in This Document . . . . . . . . . . . . . . 3
3. Data model . . . . . . . . . . . . . . . . . . . . . . . . . 3
4. Use cases . . . . . . . . . . . . . . . . . . . . . . . . . . 4
4.1. Absentee . . . . . . . . . . . . . . . . . . . . . . . . 4
4.1.1. Outgoing vacation notice . . . . . . . . . . . . . . 5
4.1.2. Outgoing preemptive vaction notice . . . . . . . . . 5
4.2. Communication partner . . . . . . . . . . . . . . . . . . 5
4.2.1. Incoming vacation notice . . . . . . . . . . . . . . 5
4.2.2. Incoming preemtive vacation notice . . . . . . . . . 5
4.2.3. Message composition . . . . . . . . . . . . . . . . . 6
5. Related use cases . . . . . . . . . . . . . . . . . . . . . . 6
5.1. Change of address . . . . . . . . . . . . . . . . . . . . 6
5.2. New contact data . . . . . . . . . . . . . . . . . . . . 6
6. Implementation guidance . . . . . . . . . . . . . . . . . . . 6
6.1. Sending . . . . . . . . . . . . . . . . . . . . . . . . . 6
6.1.1. Leave optional . . . . . . . . . . . . . . . . . . . 6
6.1.2. Provide alternative representations . . . . . . . . . 6
6.2. Processing . . . . . . . . . . . . . . . . . . . . . . . 7
6.2.1. Igore past time ranges . . . . . . . . . . . . . . . 7
6.2.2. Prefer latest vacation time range . . . . . . . . . . 7
6.2.3. Strip when forwarding . . . . . . . . . . . . . . . . 7
7. Implementation status . . . . . . . . . . . . . . . . . . . . 7
7.1. Structured Vacation Notice plugin for Roundcube
Webmail . . . . . . . . . . . . . . . . . . . . . . . . . 7
8. Security considerations . . . . . . . . . . . . . . . . . . . 8
9. Privacy considerations . . . . . . . . . . . . . . . . . . . 8
10. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 8
11. Appendix (vCard properties) . . . . . . . . . . . . . . . . . 8
12. Informative References . . . . . . . . . . . . . . . . . . . 9
Author's Address . . . . . . . . . . . . . . . . . . . . . . . . 10
1. Introduction
A "vacation notice" (also known as "out-of-office notice"
[RFC3834][RFC5598] or "-reply") is a special type of automated
message which is sent in response to incoming mail, if the recipient
is absent or otherwise unable to answer immediately.
Its content is written by the absentee in advance, before it is sent
automatically by a MUA. Many MUAs also allow to specify the exact
time period during which incoming messages should be automatically
answered with a vacation notice.
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Vacation notices are not standardized as such. [RFC5230] specifies
an extension to the Sieve email filtering language. While vacation
notices are partially formalized on the side of the absentee (e.g.,
start and end date), they consist of only human-readable language for
their recipient.
The goal of this specification is to allow absentees to include a
machine-readable version of the vacation notice, such that
reicipients can be assisted by software when dealing with vacation
notices.
While this specification may be used stand-alone, is aims to be
compliant to the "structured email" specification ([I-D.ietf-sml-
structured-email-00]) and its trust and securirty recommendations
([I-D.happel-structured-email-trust-00]).
2. Conventions Used in This Document
The term "message" refers to "electronic mail messages" or "emails"
as specified in [RFC5322].
The term "Message User Agent" (MUA) denotes an email client
application as per [RFC5598]. Based on the role of the communication
partners, one can further distiguish into "Recipient MUA" (rMUA) and
"Author MUA" (aMUA).
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.
3. Data model
The minimum data for a vacation notice is the actual notice content
as specified by the absentee. It might be as short as "I am
currently out of office".
Many systems also allow to specify a time range during which a
vacation notice should be sent. As for the Sieve vacation extension
([RFC5230]), it is often used in conjuction with a "currentdate" test
([RFC5260]) to achieve this.
Notably, this time range must not exactly match the actual absence
time, even though this is mostly the case in practice.
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Vacation notice content may also contain information about if a
message is automatically forwarded to a replacement person, or
details about replacement persons to contact.
The following snippet shows a potential extension to the [SchemaOrg]
vocabulary in [JSONLD] format.
{
"@context": "https://schema.org",
"@type": "OutOfOffice",
"start": "2023-08-15",
"end": "2023-08-22",
"isForwarded": false,
"replacement": [
{
"@type": "OutOfOfficeReplacement",
"name": "John Doe",
"topic": "Project A",
"email": "john@doe.com",
"phone": "+1234567890"
},
{
"@type": "OutOfOfficeReplacement",
"name": "Jane Doe",
"topic": "Project B",
"email": "jane@doe.com",
"phone": "+9876543210"
}
],
"note": "Some text"
}
Note: This is a preliminary specification only. Do not use in practice.
4. Use cases
For the use cases, we distinguish the absentee, willing to answer
incoming messages with a vacation notice, and communication
partner(s), which want to send messages to the absentee.
4.1. Absentee
The absentee can make use of structured vacation notices in common
vacation notice autoreplies but also in regular messages.
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4.1.1. Outgoing vacation notice
For including a structured vacation notice, a JSON-LD snippet using
the "OutOfOffice"-type defined in the previous section needs to be
embedded in the text/html representation of the vacation notice
email.
In systems using the Sieve "vacation" extension ([RFC5230]), text/
html body parts are supported when using the parameter to include
MIME content (":mime").
If the user interface already allows to set date ranges, the
structured vacation notice data may be added without extra user
effort.
4.1.2. Outgoing preemptive vaction notice
Machine-readable markup allows absentees to also include structured
vacation notices in regular messages sent before or during their
absence.
4.2. Communication partner
4.2.1. Incoming vacation notice
If an incoming vacation notice contains structured vacation notice
data, the MUA of the communication partner MAY extract and store this
data.
Since the MUA can make sense of the structured vacation notice, it
MAY also employ various forms of user assistance at its own
discretion, such as:
* Highlight the absence in a special way
* Allow to take certain action (set reminder, forward message to
replacement person)
* Inform user when composing an email to a person known to be absent
4.2.2. Incoming preemtive vacation notice
As described before, the absentee may decide to add structured
vacation notices in regular messages sent before or during her
absence.
When receiving such messages, the MUA of the communication partner
MAY extract and store the structured vacation notice and MAY
highlight the absence information.
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4.2.3. Message composition
If a communication partner wants to send a message to a person, for
which a structured vacation notice has been received earlier, the MUA
MAY notify its user about this upcoming or ongoing absence.
5. Related use cases
There are some use cases which are somehow related to "vacation
notices", mostly by providing automated messages about a certain
status of the recipient.
Those related use cases may be worth further consideration within the
design space of this draft.
5.1. Change of address
As highlightd in [RFC3834], an automated response might also convey
the fact that an email address has become obsolete or changed.
5.2. New contact data
Beyond the email addresses, senders sometimes highlight updated
information in the signature of a message, such as:
* Updated postal address
* Updated phone number
6. Implementation guidance
The following points should be considered when implementing
(structured) vacation notices from a sender and recipient-side
processing perspective.
6.1. Sending
6.1.1. Leave optional
Adding structured data to a vacation notice should be left as a
choice to the user. A MUA SHOULD not add structured data to vacation
notices without informing the user.
6.1.2. Provide alternative representations
A vacation notice including structured data should always include an
alternative, human-readable version of the vacation notice.
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6.2. Processing
6.2.1. Igore past time ranges
Ignore structured vacation notices with time ranges in the past.
6.2.2. Prefer latest vacation time range
If multiple structured vacation notices exist for a user, prefer the
one from the most recent incoming message.
6.2.3. Strip when forwarding
In the case of preemptive structured vacation notices, strip the
structured data from the message when it is forwarded to a third
party by the user.
7. Implementation status
< RFC Editor: before publication please remove this section and the
reference to [RFC7942] >
This section records the status of known implementations of the
protocol defined by this specification at the time of posting of this
Internet-Draft, and is based on a proposal described in [RFC7942].
The description of implementations in this section is intended to
assist the IETF in its decision processes in progressing drafts to
RFCs. Please note that the listing of any individual implementation
here does not imply endorsement by the IETF. Furthermore, no effort
has been spent to verify the information presented here that was
supplied by IETF contributors. This is not intended as, and must not
be construed to be, a catalog of available implementations or their
features. Readers are advised to note that other implementations may
exist.
According to [RFC7942], "this will allow reviewers and working groups
to assign due consideration to documents that have the benefit of
running code, which may serve as evidence of valuable experimentation
and feedback that have made the implemented protocols more mature.
It is up to the individual working groups to use this information as
they see fit".
7.1. Structured Vacation Notice plugin for Roundcube Webmail
This draft is implemented in an open source plugin for the Roundcube
Webmail system [RC-SVN], partly based on the Roundcube managesieve
plugin.
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8. Security considerations
In particular when using structured vacation notices in conjunction
with the Sieve filtering language, the security considerations of the
corresponding RFCs should be taken into account:
* Sieve base specification [RFC5228]
* Sieve Vacation extension [RFC5230]
* [I-D.happel-structured-email-trust-00]
9. Privacy considerations
Vacation notices expose certain potentially sensitive information to
third parties, such as absense times, absense reasons and
organizational details (such as replacement staff and their contact
information).
For this reason, absentees typically are free to decide how much
information they expose in the writte n text of their vacation
notice.
Accordingly, software systems SHOULD leave absentees the same level
of freedom when adding structured vacation notices and e.g., not
enforce the inclusion of certain information or even do so
implicitly.
Information exposure might also be limited by restricting the usage
of structured vacation notices to certain communication partners
(e.g., using address book information [RFC6134] as discussed in
[RFC6133]).
10. IANA Considerations
This document has no IANA actions at this time.
11. Appendix (vCard properties)
The following vCard "X-Properties" are currently used for internal
storage of structured vacation notice data for external contacts of
the mailbox user.
X-OOF-UPDATED:2023-10-01
X-OOF-START:2023-10-01
X-OOF-END:2023-11-01
X-OOF-IS-FORWARDED:false
X-OOF-REPLACEMENT:Jane Doe,Marketing,jane.doe@corp.com,+1234567-89
X-OOF-REPLACEMENT:John Doe,Development,john.doe@corp.com,+1234567-99
X-OOF-NOTE:I am out of office please reach my replacement instead
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12. Informative References
[JSONLD] W3C JSON-LD Working Group, "JSON-LD 1.1",
<https://www.w3.org/TR/json-ld/>.
[RC-SVN] audriga GmbH, "Structured Vacation Notice plugin for
Roundcube Webmail", <https://github.com/audriga/roundcube-
structured-vacation-notice/>.
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119,
DOI 10.17487/RFC2119, March 1997,
<https://www.rfc-editor.org/info/rfc2119>.
[RFC3834] Moore, K., "Recommendations for Automatic Responses to
Electronic Mail", RFC 3834, DOI 10.17487/RFC3834, August
2004, <https://www.rfc-editor.org/info/rfc3834>.
[RFC5228] Guenther, P., Ed. and T. Showalter, Ed., "Sieve: An Email
Filtering Language", RFC 5228, DOI 10.17487/RFC5228,
January 2008, <https://www.rfc-editor.org/info/rfc5228>.
[RFC5230] Showalter, T. and N. Freed, Ed., "Sieve Email Filtering:
Vacation Extension", RFC 5230, DOI 10.17487/RFC5230,
January 2008, <https://www.rfc-editor.org/info/rfc5230>.
[RFC5322] Resnick, P., Ed., "Internet Message Format", RFC 5322,
DOI 10.17487/RFC5322, October 2008,
<https://www.rfc-editor.org/info/rfc5322>.
[RFC5598] Crocker, D., "Internet Mail Architecture", RFC 5598,
DOI 10.17487/RFC5598, July 2009,
<https://www.rfc-editor.org/info/rfc5598>.
[RFC6133] George, R., Leiba, B., and A. Melnikov, "Sieve Email
Filtering: Use of Presence Information with Auto-Responder
Functionality", RFC 6133, DOI 10.17487/RFC6133, July 2011,
<https://www.rfc-editor.org/info/rfc6133>.
[RFC6134] Melnikov, A. and B. Leiba, "Sieve Extension: Externally
Stored Lists", RFC 6134, DOI 10.17487/RFC6134, July 2011,
<https://www.rfc-editor.org/info/rfc6134>.
[RFC7942] Sheffer, Y. and A. Farrel, "Improving Awareness of Running
Code: The Implementation Status Section", BCP 205,
RFC 7942, DOI 10.17487/RFC7942, July 2016,
<https://www.rfc-editor.org/info/rfc7942>.
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[RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC
2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174,
May 2017, <https://www.rfc-editor.org/info/rfc8174>.
[SchemaOrg]
W3C Schema.org Community Group, "Schema.org",
<https://schema.org/>.
Author's Address
Hans-Joerg Happel
audriga GmbH
Email: happel@audriga.com
URI: https://www.audriga.com
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