< draft-ietf-extra-sieve-snooze-00.txt		draft-ietf-extra-sieve-snooze-01.txt >
	EXTRA K. Murchison		EXTRA K. Murchison
	Internet-Draft R. Signes		Internet-Draft R. Signes
	Updates: 5232 (if approved) N. Jenkins		Updates: 5232 (if approved) N. Jenkins
	Intended status: Standards Track Fastmail		Intended status: Standards Track Fastmail
	Expires: February 8, 2021 August 7, 2020		Expires: August 26, 2021 February 22, 2021
	Sieve Email Filtering: Snooze Extension		Sieve Email Filtering: Snooze Extension
	draft-ietf-extra-sieve-snooze-00		draft-ietf-extra-sieve-snooze-01
	Abstract		Abstract
	This document describes the "snooze" extension to the Sieve email		This document describes the "snooze" extension to the Sieve email
	filtering language. The "snooze" extension gives Sieve the ability		filtering language. The "snooze" extension gives Sieve the ability
	to postpone the filing of an incoming into a target mailbox until a		to postpone the delivery of an incoming into a target mailbox until a
	later point in time.		later point in time.
	Status of This Memo		Status of This Memo
	This Internet-Draft is submitted in full conformance with the		This Internet-Draft is submitted in full conformance with the
	provisions of BCP 78 and BCP 79.		provisions of BCP 78 and BCP 79.
	Internet-Drafts are working documents of the Internet Engineering		Internet-Drafts are working documents of the Internet Engineering
	Task Force (IETF). Note that other groups may also distribute		Task Force (IETF). Note that other groups may also distribute
	working documents as Internet-Drafts. The list of current Internet-		working documents as Internet-Drafts. The list of current Internet-
	Drafts is at https://datatracker.ietf.org/drafts/current/.		Drafts is at https://datatracker.ietf.org/drafts/current/.
	Internet-Drafts are draft documents valid for a maximum of six months		Internet-Drafts are draft documents valid for a maximum of six months
	and may be updated, replaced, or obsoleted by other documents at any		and may be updated, replaced, or obsoleted by other documents at any
	time. It is inappropriate to use Internet-Drafts as reference		time. It is inappropriate to use Internet-Drafts as reference
	material or to cite them other than as "work in progress."		material or to cite them other than as "work in progress."
	This Internet-Draft will expire on February 8, 2021.		This Internet-Draft will expire on August 26, 2021.
	Copyright Notice		Copyright Notice
	Copyright (c) 2020 IETF Trust and the persons identified as the		Copyright (c) 2021 IETF Trust and the persons identified as the
	document authors. All rights reserved.		document authors. All rights reserved.
	This document is subject to BCP 78 and the IETF Trust's Legal		This document is subject to BCP 78 and the IETF Trust's Legal
	Provisions Relating to IETF Documents		Provisions Relating to IETF Documents
	(https://trustee.ietf.org/license-info) in effect on the date of		(https://trustee.ietf.org/license-info) in effect on the date of
	publication of this document. Please review these documents		publication of this document. Please review these documents
	carefully, as they describe your rights and restrictions with respect		carefully, as they describe your rights and restrictions with respect
	to this document. Code Components extracted from this document must		to this document. Code Components extracted from this document must
	include Simplified BSD License text as described in Section 4.e of		include Simplified BSD License text as described in Section 4.e of
	the Trust Legal Provisions and are provided without warranty as		the Trust Legal Provisions and are provided without warranty as
	described in the Simplified BSD License.		described in the Simplified BSD License.
	Table of Contents		Table of Contents
	1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2		1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
	2. Conventions Used in This Document . . . . . . . . . . . . . . 2		2. Conventions Used in This Document . . . . . . . . . . . . . . 2
	3. Snooze Action . . . . . . . . . . . . . . . . . . . . . . . . 3		3. Capability Identifier . . . . . . . . . . . . . . . . . . . . 3
	3.1. Mailbox Argument . . . . . . . . . . . . . . . . . . . . 3		4. Snooze Action . . . . . . . . . . . . . . . . . . . . . . . . 3
	3.2. Weekdays Argument . . . . . . . . . . . . . . . . . . . . 4		4.1. Mailbox Argument . . . . . . . . . . . . . . . . . . . . 3
	3.3. Times and TZID Arguments . . . . . . . . . . . . . . . . 4		4.2. Weekdays Argument . . . . . . . . . . . . . . . . . . . . 4
	3.3.1. Awaken Times Examples . . . . . . . . . . . . . . . . 4		4.3. Times and TZID Arguments . . . . . . . . . . . . . . . . 4
	3.4. Interaction with Extensions to the Fileinto Action . . . 5		4.3.1. Awaken Times Examples . . . . . . . . . . . . . . . . 5
	3.4.1. Imap4flags Extension . . . . . . . . . . . . . . . . 6		4.4. Interaction with Extensions to the Fileinto Action . . . 6
	3.4.2. Mailbox Extension . . . . . . . . . . . . . . . . . . 6		4.4.1. Imap4flags Extension . . . . . . . . . . . . . . . . 6
	3.4.3. Special-Use Extension . . . . . . . . . . . . . . . . 7		4.4.2. Mailbox Extension . . . . . . . . . . . . . . . . . . 7
	3.4.4. MailboxID Extension . . . . . . . . . . . . . . . . . 7		4.4.3. Special-Use Extension . . . . . . . . . . . . . . . . 7
	4. Mechanics of Snoozing Messages . . . . . . . . . . . . . . . 7		4.4.4. MailboxID Extension . . . . . . . . . . . . . . . . . 8
	4.1. SMTP Future Message Release . . . . . . . . . . . . . . . 8
	4.2. "Snoozed" Mailbox . . . . . . . . . . . . . . . . . . . . 8
	5. Implementation Status . . . . . . . . . . . . . . . . . . . . 8		5. Implementation Status . . . . . . . . . . . . . . . . . . . . 8
	6. Security Considerations . . . . . . . . . . . . . . . . . . . 9		6. Security Considerations . . . . . . . . . . . . . . . . . . . 9
	7. Privacy Considerations . . . . . . . . . . . . . . . . . . . 9		7. Privacy Considerations . . . . . . . . . . . . . . . . . . . 9
	8. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 9		8. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 9
	8.1. Registration of Sieve Extension . . . . . . . . . . . . . 9		8.1. Registration of Sieve Extension . . . . . . . . . . . . . 9
	9. References . . . . . . . . . . . . . . . . . . . . . . . . . 9		8.2. Registration of IMAP Mailbox Name Attribute . . . . . . . 10
	9.1. Normative References . . . . . . . . . . . . . . . . . . 10		9. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 10
	9.2. Informative References . . . . . . . . . . . . . . . . . 11		10. References . . . . . . . . . . . . . . . . . . . . . . . . . 10
	9.3. URIs . . . . . . . . . . . . . . . . . . . . . . . . . . 11		10.1. Normative References . . . . . . . . . . . . . . . . . . 10
	Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 11		10.2. Informative References . . . . . . . . . . . . . . . . . 12
			10.3. URIs . . . . . . . . . . . . . . . . . . . . . . . . . . 12
			Appendix A. Change History (To be removed by RFC Editor before
			publication) . . . . . . . . . . . . . . . . . . . . 12
			Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 12
	1. Introduction		1. Introduction
	Users are not always ready, willing, or able to read and respond to		Users are not always ready, willing, or able to read and respond to
	email messages at the time of their arrival. Sometimes it is		email messages at the time of their arrival. Sometimes it is
	desirable to have messages appear in a mailbox at a more convenient		desirable to have messages appear in a mailbox at a more convenient
	time for the user to act upon them.		time for the user to act upon them.
	This document defines a new Sieve action command "snooze" that		This document defines an extension to the Sieve language [RFC5228]
	postpones filing a message into a target mailbox until a later point		that enables scripts to postpone the delivery of a message into a
	in time. The capability string associated with this extension is		target mailbox until a later point in time.
	"snooze".
	2. Conventions Used in This Document		2. Conventions Used in This Document
	Conventions for notations are as in Section 1.1 of [RFC5228],		Conventions for notations are as in Section 1.1 of [RFC5228],
	including use of the "Usage:" label for the definition of action and		including use of the "Usage:" label for the definition of action and
	tagged arguments syntax.		tagged arguments syntax.
	The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",		The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
	"SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and		"SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and
	"OPTIONAL" in this document are to be interpreted as described in		"OPTIONAL" in this document are to be interpreted as described in
	BCP 14 [RFC2119] [RFC8174] when, and only when, they appear in all		BCP 14 [RFC2119] [RFC8174] when, and only when, they appear in all
	capitals, as shown here.		capitals, as shown here.
	3. Snooze Action		3. Capability Identifier
			Sieve implementations that implement this extension have an
			identifier of "snooze" for use with the capability mechanism.
			4. Snooze Action
	Usage: snooze *AWAKEN-OPTIONS <times: string-list>		Usage: snooze *AWAKEN-OPTIONS <times: string-list>
	The AWAKEN-OPTIONS argument is defined here in ABNF [RFC4234] syntax		The AWAKEN-OPTIONS argument is defined here in ABNF [RFC4234] syntax
	so that it can be modified by other extensions.		so that it can be modified by other extensions.
	AWAKEN-OPTIONS = MAILBOX / WEEKDAYS / TZID		AWAKEN-OPTIONS = MAILBOX / WEEKDAYS / TZID
	; each option MUST NOT appear more than once		; each option MUST NOT appear more than once
	; however, per Section 2.6.2 of RFC 5228,		; however, per Section 2.6.2 of RFC 5228,
	; the tagged arguments in AWAKEN-OPTIONS		; the tagged arguments in AWAKEN-OPTIONS
	; may appear in any order		; may appear in any order
	MAILBOX = ":mailbox" string		MAILBOX = ":mailbox" string
	WEEKDAYS = ":weekdays" string-list		WEEKDAYS = ":weekdays" string-list
	TZID = ":tzid" string		TZID = ":tzid" string
			The "snooze" action cancels the implicit keep and postpones delivery
			of the message into the specified mailbox at a later point in time.
	The snooze action is semantically equivalent to a delayed fileinto		The snooze action is semantically equivalent to a delayed fileinto
	action (see Section 4.1 of [RFC5228]). The arguments of the snooze		action (see Section 4.1 of [RFC5228]). The arguments of the snooze
	action specify when, where, and how the awakened message will be		action specify when, where, and how the awakened message will be
	filed.		filed.
	The process of actually snoozing and awakening (delaying the filing		A Sieve interpreter MUST implement the snooze action by delivering
	of) the message is implementation specific and outside the scope of		the message to a special "snoozed" mailbox within its mailstore.
	this document. However, Section 4 discusses possible methods for		IMAP and JMAP servers MUST apply the "Snoozed" (Section 8.2)
	implementing the snooze action.		attribute to this mailbox. The message will reside in this special
			mailbox until the prescribed awaken time at which it will be moved
			into the specified target mailbox.
	3.1. Mailbox Argument		4.1. Mailbox Argument
	The optional :mailbox argument is used to specify the target mailbox		The optional :mailbox argument is used to specify the target mailbox
	that the message will be filed into when it is awakened. It is		that the message will be filed into when it is awakened. It is
	equivalent to the mailbox argument of the fileinto action (see		equivalent to the mailbox argument of the fileinto action (see
	Section 4.1 of [RFC5228]).		Section 4.1 of [RFC5228]).
	If :mailbox is omitted, or if the specified mailbox doesn't exist at		If :mailbox is omitted, or if the specified mailbox doesn't exist at
	the time of awakening, the message will be filed into the user's main		the time of awakening, the message will be filed into the user's main
	mailbox. For instance, in an implementation where the IMAP server is		mailbox. For instance, in an implementation where the IMAP server is
	running scripts on behalf of the user at time of delivery, the user's		running scripts on behalf of the user at time of delivery, the user's
	"INBOX" would be the implicit target for awakening messages.		"INBOX" would be the implicit target for awakening messages.
	3.2. Weekdays Argument		4.2. Weekdays Argument
	The optional :weekdays argument specifies the set of days on which		The optional :weekdays argument specifies the set of days on which
	the specified set of awakening times apply. Each day of the week is		the specified set of awakening times apply. Each day of the week is
	expressed as an integer between "0" and "6". "0" is Sunday, "1" is		expressed as an integer between "0" and "6". "0" is Sunday, "1" is
	Monday, etc. This syntax matches that of the "weekday" date-part		Monday, etc. This syntax matches that of the "weekday" date-part
	argument to the date test extension (see Section 4.2 of [RFC5260]).		argument to the date test extension (see Section 4.2 of [RFC5260]).
	If :weekdays is omitted, the set of awakening times applies to every		If :weekdays is omitted, the set of awakening times applies to every
	day of the week.		day of the week.
	3.3. Times and TZID Arguments		4.3. Times and TZID Arguments
	The required times argument, along with the optional :tzid argument,		The required times argument, along with the optional :tzid argument,
	are used to specify when a snoozed message will be awakened. Each		are used to specify when a snoozed message will be awakened. Each
	time is specified in "hh:mm:ss" format and is interpreted as the		time is specified in "hh:mm:ss" format and is interpreted as the
	local time in the time zone specified by the :tzid argument.		local time in the time zone specified by the :tzid argument.
	The value of the :tzid argument MUST be a time zone identifier from		The value of the :tzid argument MUST be a time zone identifier from
	the IANA Time Zone Database [tzdb]. If :tzid is omitted, the time		the IANA Time Zone Database [tzdb]. If :tzid is omitted, the time
	zone of the Sieve interpreter is used.		zone of the Sieve interpreter is used.
	skipping to change at page 4, line 40 ¶		skipping to change at page 5, line 5 ¶
	with no awaken times, or after the last awaken time on a given day,		with no awaken times, or after the last awaken time on a given day,
	the first awaken time on the next available day is used.		the first awaken time on the next available day is used.
	If the local time in the specified time zone occurs more than once		If the local time in the specified time zone occurs more than once
	(daylight saving to standard time transition), the first occurrence		(daylight saving to standard time transition), the first occurrence
	of the specified time value is used. If the local time in the		of the specified time value is used. If the local time in the
	specified time zone does not occur (standard to daylight saving time		specified time zone does not occur (standard to daylight saving time
	transition), the specified time value is interpreted using the UTC		transition), the specified time value is interpreted using the UTC
	offset prior to the transition.		offset prior to the transition.
	3.3.1. Awaken Times Examples		4.3.1. Awaken Times Examples
	The following examples show, given the specified snooze action and a		The following examples show, given the specified snooze action and a
	set of message arrival times, the corresponding times at which the		set of message arrival times, the corresponding times at which the
	message would be awakened and filed.		message would be awakened and filed.
	The following example shows awaken times rolling into the next day or		The following example shows awaken times rolling into the next day or
	week. Note that 2020-07-30 falls on a Thursday.		week. Note that 2020-07-30 falls on a Thursday.
	require "snooze";		require "snooze";
	snooze :weekdays ["1", "3", "5", "2", "4"]		snooze :weekdays ["1", "3", "5", "2", "4"]
	skipping to change at page 5, line 36 ¶		skipping to change at page 6, line 4 ¶
	| 2020-11-01T06:00:00Z | --11-01T01:00:00-05 | --11-02T01:30:00-05 |		| 2020-11-01T06:00:00Z | --11-01T01:00:00-05 | --11-02T01:30:00-05 |
	| 2020-11-01T07:00:00Z | --11-01T02:00:00-05 | --11-02T01:30:00-05 |		| 2020-11-01T07:00:00Z | --11-01T02:00:00-05 | --11-02T01:30:00-05 |
	+----------------------+---------------------+---------------------+		+----------------------+---------------------+---------------------+
	The following example shows awaken times falling before, during, and		The following example shows awaken times falling before, during, and
	after a standard to daylight saving time transition. Note that the		after a standard to daylight saving time transition. Note that the
	transition occurs at 2021-03-14T02:00:00-05.		transition occurs at 2021-03-14T02:00:00-05.
	require "snooze";		require "snooze";
	snooze :tzid "America/New_York" "02:30:00";		snooze :tzid "America/New_York" "02:30:00";
	+----------------------+---------------------+---------------------+		+----------------------+---------------------+---------------------+
	| Arrival (UTC) | Arrival (New York) | Awaken (New York) |		| Arrival (UTC) | Arrival (New York) | Awaken (New York) |
	+----------------------+---------------------+---------------------+		+----------------------+---------------------+---------------------+
	| 2021-03-13T06:30:00Z | --03-13T01:30:00-05 | --03-13T02:30:00-05 |		| 2021-03-13T06:30:00Z | --03-13T01:30:00-05 | --03-13T02:30:00-05 |
	| 2021-03-14T06:30:00Z | --03-14T01:30:00-05 | --03-14T03:30:00-04 |		| 2021-03-14T06:30:00Z | --03-14T01:30:00-05 | --03-14T03:30:00-04 |
	| 2021-03-14T07:30:00Z | --03-14T03:30:00-04 | --03-15T02:30:00-04 |		| 2021-03-14T07:30:00Z | --03-14T03:30:00-04 | --03-15T02:30:00-04 |
	+----------------------+---------------------+---------------------+		+----------------------+---------------------+---------------------+
	3.4. Interaction with Extensions to the Fileinto Action		4.4. Interaction with Extensions to the Fileinto Action
	Some tagged arguments defined in extensions to the fileinto action		Some tagged arguments defined in extensions to the fileinto action
	can be used together with the snooze action. The sections below		can be used together with the snooze action. The sections below
	describe these interactions. Tagged arguments in future extensions		describe these interactions. Tagged arguments in future extensions
	to the fileinto action need to describe their interaction with the		to the fileinto action need to describe their interaction with the
	snooze extension, if any.		snooze extension, if any.
	When any fileinto extension arguments are used with the snooze		When any fileinto extension arguments are used with the snooze
	extension, the corresponding extension MUST be enabled, and the		extension, the corresponding extension MUST be enabled, and the
	arguments are defined to have the same syntax, semantics, and		arguments are defined to have the same syntax, semantics, and
	treatment as they do with the fileinto action.		treatment as they do with the fileinto action.
	3.4.1. Imap4flags Extension		4.4.1. Imap4flags Extension
	When the "imap4flags" [RFC5232] extension is enabled in a script, two		When the "imap4flags" [RFC5232] extension is enabled in a script, two
	additional tagged arguments are added to "snooze" that allow		additional tagged arguments are added to "snooze" that allow
	manipulating the set of flags on a snoozed message.		manipulating the set of flags on a snoozed message.
	AWAKEN-OPTIONS /= ADDFLAGS / REMOVEFLAGS		AWAKEN-OPTIONS /= ADDFLAGS / REMOVEFLAGS
	ADDFLAGS = ":addflags" string-list		ADDFLAGS = ":addflags" string-list
	REMOVEFLAGS = ":removeflags" string-list		REMOVEFLAGS = ":removeflags" string-list
			If the "setflag" and/or "addflag" actions have been used to store
			IMAP flags in the imap4flags internal variable, the Sieve interpreter
			MUST use the current value of the internal variable as the set of
			flags to associate with the message when storing it into the
			"snoozed" mailbox.
	The optional :addflags and :removeflags arguments are used to specify		The optional :addflags and :removeflags arguments are used to specify
	which IMAP [RFC3501] flags should be added to and/or removed from the		which IMAP [RFC3501] flags should be added to and/or removed from the
	set of IMAP flags present on the snoozed message at the time of		set of IMAP flags present on the snoozed message at the time of
	awakening. Note that depending on the method used to snooze a		awakening. Note the set of IMAP flags present at the time of
	message, the set of IMAP flags present at the time of awakening may		awakening may be the empty set.
	be the empty set.
	This document doesn't dictate how the Sieve interpreter will set the		This document doesn't dictate how the Sieve interpreter will set the
	IMAP flags. In particular, the Sieve interpreter may work as an IMAP		IMAP flags. In particular, the Sieve interpreter may work as an IMAP
	client or may have direct access to the mailstore.		client or may have direct access to the mailstore.
	The general requirements for flag handling specified in Section 2 of		The general requirements for flag handling specified in Section 2 of
	[RFC5232] MUST be followed.		[RFC5232] MUST be followed.
	3.4.2. Mailbox Extension		4.4.1.1. Example
			The following example leverage the Date [RFC5260], Relational
			[RFC5231], and Imap4flags [RFC5232] extensions to snooze messages
			received after business hours until the following work day. Note
			that the message is marked as important when it is snoozed, and will
			be marked as unread when it is awakened.
			require ["snooze", "imap4flags", "date", "relational"];
			if anyof(header :is "from" "boss@example.com",
			currentdate :is "weekday" "0",
			currentdate :is "weekday" "6",
			currentdate :value "ge" "hour" "17") {
			setflag "\\Important";
			snooze :removeflags "\\Seen"
			:weekdays ["1". "2", "3", "4", "5"]
			:tzid "American/New_York", "09:00";
			}
			4.4.2. Mailbox Extension
	This document extends the definition of the ":create" [RFC5490]		This document extends the definition of the ":create" [RFC5490]
	tagged argument so that it can be used with the snooze action.		tagged argument so that it can be used with the snooze action.
	AWAKEN-OPTIONS /= CREATE		AWAKEN-OPTIONS /= CREATE
	CREATE = ":create"		CREATE = ":create"
	; MUST NOT be appear unless MAILBOX also appears		; MUST NOT be appear unless MAILBOX also appears
	If the optional ":create" argument is specified with snooze, it		If the optional ":create" argument is specified with snooze, it
	instructs the Sieve interpreter to create the target mailbox, if		instructs the Sieve interpreter to create the target mailbox, if
	needed, before attempting to file the awakened message into the		needed, before attempting to file the awakened message into the
	target mailbox.		target mailbox.
	3.4.3. Special-Use Extension		4.4.3. Special-Use Extension
	This document extends the definition of the ":specialuse" [RFC8579]		This document extends the definition of the ":specialuse" [RFC8579]
	tagged argument so that it can be used with the snooze action.		tagged argument so that it can be used with the snooze action.
	AWAKEN-OPTIONS /= SPECIAL-USE		AWAKEN-OPTIONS /= SPECIAL-USE
	SPECIAL-USE = ":specialuse" string		SPECIAL-USE = ":specialuse" string
	If the optional ":specialuse" argument is specified with snooze, it		If the optional ":specialuse" argument is specified with snooze, it
	instructs the Sieve interpreter to check whether a mailbox exists		instructs the Sieve interpreter to check whether a mailbox exists
	with the specific special-use flag assigned to it. If such a mailbox		with the specific special-use flag assigned to it. If such a mailbox
	exists, the awakened message is filed into the special-use mailbox.		exists, the awakened message is filed into the special-use mailbox.
	Otherwise, the awakened message is filed into the target mailbox.		Otherwise, the awakened message is filed into the target mailbox.
	If both the optional ":specialuse" and ":create" arguments are		If both the optional ":specialuse" and ":create" arguments are
	specified with snooze, the Sieve interpreter is instructed to create		specified with snooze, the Sieve interpreter is instructed to create
	the target mailbox per Section 4.1 of [RFC8579], if needed.		the target mailbox per Section 4.1 of [RFC8579], if needed.
	3.4.4. MailboxID Extension		4.4.4. MailboxID Extension
	This document extends the definition of the ":mailboxid"		This document extends the definition of the ":mailboxid"
	[I-D.gondwana-sieve-mailboxid] tagged argument so that it can be used		[I-D.ietf-extra-sieve-mailboxid] tagged argument so that it can be
	with the snooze action.		used with the snooze action.
	AWAKEN-OPTIONS /= MAILBOXID		AWAKEN-OPTIONS /= MAILBOXID
	MAILBOXID = ":mailboxid" string		MAILBOXID = ":mailboxid" string
	If the optional ":mailboxid" argument is specified with snooze, it		If the optional ":mailboxid" argument is specified with snooze, it
	instructs the Sieve interpreter to check whether a mailbox exists in		instructs the Sieve interpreter to check whether a mailbox exists in
	the user's personal namespace [RFC2342] with the specified MAILBOXID		the user's personal namespace [RFC2342] with the specified MAILBOXID
	[RFC8474]. If such a mailbox exists, the awakened message is filed		[RFC8474]. If such a mailbox exists, the awakened message is filed
	into that mailbox. Otherwise, the awakened message is filed into the		into that mailbox. Otherwise, the awakened message is filed into the
	target mailbox.		target mailbox.
	If both the optional ":mailboxid" and ":specialuse" arguments are		It is an error to specify both ":mailboxid" and ":specialuse" in the
	specified with snooze, the Sieve interpreter is instructed to resolve		same snooze action.
	the mailboxid first. If a mailbox with the specified mailboxid does
	not exist, then the process in Section 3.4.3 is followed.
	4. Mechanics of Snoozing Messages
	The process of snoozing is implementation specific and outside the
	scope of this document. However, the sections below outline possible
	methods of snoozing and awakening a message to be filed.
	4.1. SMTP Future Message Release
	A Sieve interpreter may implement the snooze action by leveraging the
	SMTP Future Message Release [RFC4865] submission extension. The
	message would be snoozed by queuing it for redelivery with a release
	time that corresponds to the calculated awaken time. The target
	mailbox for the awakened message would need to be encoded into the
	recipient address or into a message header field. Care MUST be taken
	to prevent the awakened message from being re-snoozed by the Sieve
	script and causing a message loop.
	4.2. "Snoozed" Mailbox
	A Sieve interpreter may implement the snooze action by leveraging the
	user's existing mail store. The message would be snoozed by storing
	the message in a special "snoozed" mailbox and then moved into the
	target mailbox at the calculated awaken time.
	If a user's Sieve script enables the "imap4flags" [RFC5232]
	extension, and if the "setflag" and/or "addflag" actions have been
	used to store IMAP flags in the imap4flags internal variable, the
	Sieve interpreter MAY use the current value of the internal variable
	as the set of flags to associate with the message when storing it
	into the "snoozed" mailbox. Note that in this case, the ":addflag"
	and ":removeflag" tagged arguments to the snooze action operate on
	this set of flags, but MUST NOT do so until the message is awakened.
	5. Implementation Status		5. Implementation Status
	< RFC Editor: before publication please remove this section and the		< RFC Editor: before publication please remove this section and the
	reference to [RFC7942] >		reference to [RFC7942] >
	This section records the status of known implementations of the		This section records the status of known implementations of the
	protocol defined by this specification at the time of posting of this		protocol defined by this specification at the time of posting of this
	Internet-Draft, and is based on a proposal described in [RFC7942].		Internet-Draft, and is based on a proposal described in [RFC7942].
	The description of implementations in this section is intended to		The description of implementations in this section is intended to
	skipping to change at page 9, line 20 ¶		skipping to change at page 9, line 24 ¶
	The open source Cyrus Server [1] project is a highly scalable		The open source Cyrus Server [1] project is a highly scalable
	enterprise mail system which supports Sieve email filtering at the		enterprise mail system which supports Sieve email filtering at the
	point of final delivery. This production level Sieve implementation		point of final delivery. This production level Sieve implementation
	supports all of the requirements described in this document. This		supports all of the requirements described in this document. This
	implementation is freely distributable under a BSD style license from		implementation is freely distributable under a BSD style license from
	Computing Services at Carnegie Mellon University [2].		Computing Services at Carnegie Mellon University [2].
	6. Security Considerations		6. Security Considerations
	Security considerations are discussed in [RFC5228], [RFC5232],		Security considerations are discussed in [RFC5228], [RFC5232],
	[RFC8579], and [I-D.gondwana-sieve-mailboxid].		[RFC8579], and [I-D.ietf-extra-sieve-mailboxid].
	It is believed that this extension doesn't introduce any additional		It is believed that this extension doesn't introduce any additional
	security concerns.		security concerns.
	7. Privacy Considerations		7. Privacy Considerations
	It is believed that this extension doesn't introduce any privacy		It is believed that this extension doesn't introduce any privacy
	considerations beyond those in [RFC5228].		considerations beyond those in [RFC5228].
	8. IANA Considerations		8. IANA Considerations
	8.1. Registration of Sieve Extension		8.1. Registration of Sieve Extension
			This document defines the following new Sieve extension to be added
			to the registry defined in Section 6.2 of [RFC5228] and located here:
			<https://www.iana.org/assignments/sieve-extensions/sieve-
			extensions.xhtml#sieve-extensions>
			IANA are requested to add a capability to the Sieve Extensions
			registry:
	To: iana@iana.org		To: iana@iana.org
	Subject: Registration of new Sieve extension		Subject: Registration of new Sieve extension
	Capability name: snooze		Capability name: snooze
			Description: Adds the "snooze" action command to postpone delivery
	Description: Adds the "snooze" action command to postpone filing a		of a message into a target mailbox until a later point in time.
	message into a target mailbox until a later point in time.
	RFC number: RFC XXXX		RFC number: RFC XXXX
	Contact address: The Sieve discussion list <sieve@ietf.org>		Contact address: The Sieve discussion list <sieve@ietf.org>
	9. References		8.2. Registration of IMAP Mailbox Name Attribute
	9.1. Normative References
	[I-D.gondwana-sieve-mailboxid]		This document defines the following new IMAP mailbox name attribute
			to be added to the registry defined in Section 6.2 of [RFC8457] and
			located here: <https://www.iana.org/assignments/imap-mailbox-name-
			attributes/imap-mailbox-name-attributes.xhtml#imap-mailbox-name-
			attributes>
			IANA are requested to add an attribute to the IMAP Mailbox Name
			Attribute registry:
			To: iana@iana.org
			Subject: Registration of new IMAP Mailbox Name Attribute
			Attribute name: Snoozed
			Description: Messages that have been snoozed.
			Reference: RFC XXXX
			9. Acknowledgments
			The authors would like to thank the following individuals for
			contributing their ideas and support for writing this specification:
			Ned Freed, Barry Leiba, and Alexey Melnikov.
			10. References
			10.1. Normative References
			[I-D.ietf-extra-sieve-mailboxid]
	Gondwana, B., "Sieve Email Filtering: delivery by		Gondwana, B., "Sieve Email Filtering: delivery by
	mailboxid", draft-gondwana-sieve-mailboxid-02 (work in		mailboxid", draft-ietf-extra-sieve-mailboxid-06 (work in
	progress), June 2020.		progress), December 2020.
	[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate		[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
	Requirement Levels", BCP 14, RFC 2119,		Requirement Levels", BCP 14, RFC 2119,
	DOI 10.17487/RFC2119, March 1997,		DOI 10.17487/RFC2119, March 1997,
	<https://www.rfc-editor.org/info/rfc2119>.		<https://www.rfc-editor.org/info/rfc2119>.
	[RFC2342] Gahrns, M. and C. Newman, "IMAP4 Namespace", RFC 2342,		[RFC2342] Gahrns, M. and C. Newman, "IMAP4 Namespace", RFC 2342,
	DOI 10.17487/RFC2342, May 1998,		DOI 10.17487/RFC2342, May 1998,
	<https://www.rfc-editor.org/info/rfc2342>.		<https://www.rfc-editor.org/info/rfc2342>.
	skipping to change at page 10, line 45 ¶		skipping to change at page 11, line 34 ¶
	[RFC5490] Melnikov, A., "The Sieve Mail-Filtering Language --		[RFC5490] Melnikov, A., "The Sieve Mail-Filtering Language --
	Extensions for Checking Mailbox Status and Accessing		Extensions for Checking Mailbox Status and Accessing
	Mailbox Metadata", RFC 5490, DOI 10.17487/RFC5490, March		Mailbox Metadata", RFC 5490, DOI 10.17487/RFC5490, March
	2009, <https://www.rfc-editor.org/info/rfc5490>.		2009, <https://www.rfc-editor.org/info/rfc5490>.
	[RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC		[RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC
	2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174,		2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174,
	May 2017, <https://www.rfc-editor.org/info/rfc8174>.		May 2017, <https://www.rfc-editor.org/info/rfc8174>.
			[RFC8457] Leiba, B., Ed., "IMAP "$Important" Keyword and
			"\Important" Special-Use Attribute", RFC 8457,
			DOI 10.17487/RFC8457, September 2018,
			<https://www.rfc-editor.org/info/rfc8457>.
	[RFC8474] Gondwana, B., Ed., "IMAP Extension for Object		[RFC8474] Gondwana, B., Ed., "IMAP Extension for Object
	Identifiers", RFC 8474, DOI 10.17487/RFC8474, September		Identifiers", RFC 8474, DOI 10.17487/RFC8474, September
	2018, <https://www.rfc-editor.org/info/rfc8474>.		2018, <https://www.rfc-editor.org/info/rfc8474>.
	[RFC8579] Bosch, S., "Sieve Email Filtering: Delivering to Special-		[RFC8579] Bosch, S., "Sieve Email Filtering: Delivering to Special-
	Use Mailboxes", RFC 8579, DOI 10.17487/RFC8579, May 2019,		Use Mailboxes", RFC 8579, DOI 10.17487/RFC8579, May 2019,
	<https://www.rfc-editor.org/info/rfc8579>.		<https://www.rfc-editor.org/info/rfc8579>.
	[tzdb] Internet Assigned Numbers Authority, "Time Zone Database",		[tzdb] Internet Assigned Numbers Authority, "Time Zone Database",
	<https://www.iana.org/time-zones>.		<https://www.iana.org/time-zones>.
	9.2. Informative References		10.2. Informative References
	[RFC4865] White, G. and G. Vaudreuil, "SMTP Submission Service		[RFC5231] Segmuller, W. and B. Leiba, "Sieve Email Filtering:
	Extension for Future Message Release", RFC 4865,		Relational Extension", RFC 5231, DOI 10.17487/RFC5231,
	DOI 10.17487/RFC4865, May 2007,		January 2008, <https://www.rfc-editor.org/info/rfc5231>.
	<https://www.rfc-editor.org/info/rfc4865>.
	[RFC5260] Freed, N., "Sieve Email Filtering: Date and Index		[RFC5260] Freed, N., "Sieve Email Filtering: Date and Index
	Extensions", RFC 5260, DOI 10.17487/RFC5260, July 2008,		Extensions", RFC 5260, DOI 10.17487/RFC5260, July 2008,
	<https://www.rfc-editor.org/info/rfc5260>.		<https://www.rfc-editor.org/info/rfc5260>.
	[RFC7942] Sheffer, Y. and A. Farrel, "Improving Awareness of Running		[RFC7942] Sheffer, Y. and A. Farrel, "Improving Awareness of Running
	Code: The Implementation Status Section", BCP 205,		Code: The Implementation Status Section", BCP 205,
	RFC 7942, DOI 10.17487/RFC7942, July 2016,		RFC 7942, DOI 10.17487/RFC7942, July 2016,
	<https://www.rfc-editor.org/info/rfc7942>.		<https://www.rfc-editor.org/info/rfc7942>.
	9.3. URIs		10.3. URIs
	[1] http://www.cyrusimap.org/		[1] http://www.cyrusimap.org/
	[2] http://www.cmu.edu/computing/		[2] http://www.cmu.edu/computing/
	Authors' Addresses		Appendix A. Change History (To be removed by RFC Editor before
			publication)
			Changes since draft-ietf-extra-sieve-snooze-00:
			o Disallow both :mailboxid and :specialuse in the same snooze
			action.
			o Updated :mailboxid reference to draft-ietf-extra-sieve-mailboxid
			o Specified that snooze cancels implicit keep.
			o Specified that implementations MUST use a "snoozed" mailbox.
			o Added registration of \Snoozed Special-Use Attribute.
			o Added example of manipulating IMAP flags at both snooze time and
			awaken time.
			o Miscellaneous editorial changes.
			Authors' Addresses
	Kenneth Murchison		Kenneth Murchison
	Fastmail US LLC		Fastmail US LLC
	1429 Walnut Street - Suite 1201		1429 Walnut Street - Suite 1201
	Philadelphia, PA 19102		Philadelphia, PA 19102
	USA		USA
	Email: murch@fastmailteam.com		Email: murch@fastmailteam.com
	Ricardo Signes		Ricardo Signes
	Fastmail US LLC		Fastmail US LLC
End of changes. 38 change blocks.
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