···1+2+3+4+5+MailMaint N.M. Jenkins, Ed.
6+Internet-Draft Fastmail
7+Intended status: Informational D. Eggert, Ed.
8+Expires: 21 August 2025 Apple Inc
9+ 17 February 2025
10+11+12+ Registration of further IMAP/JMAP keywords and mailbox attribute names
13+ draft-ietf-mailmaint-messageflag-mailboxattribute-02
14+15+Abstract
16+17+ This document defines a number of keywords that have been in use by
18+ Fastmail and Apple respectively for some time. It defines their
19+ intended use. Additionally some mailbox names with special meaning
20+ have been in use by Fastmail, and this document defines their
21+ intended use. This document registers all of these names with IANA
22+ to avoid name collisions.
23+24+Status of This Memo
25+26+ This Internet-Draft is submitted in full conformance with the
27+ provisions of BCP 78 and BCP 79.
28+29+ Internet-Drafts are working documents of the Internet Engineering
30+ Task Force (IETF). Note that other groups may also distribute
31+ working documents as Internet-Drafts. The list of current Internet-
32+ Drafts is at https://datatracker.ietf.org/drafts/current/.
33+34+ Internet-Drafts are draft documents valid for a maximum of six months
35+ and may be updated, replaced, or obsoleted by other documents at any
36+ time. It is inappropriate to use Internet-Drafts as reference
37+ material or to cite them other than as "work in progress."
38+39+ This Internet-Draft will expire on 21 August 2025.
40+41+Copyright Notice
42+43+ Copyright (c) 2025 IETF Trust and the persons identified as the
44+ document authors. All rights reserved.
45+46+47+48+49+50+51+52+53+54+55+56+Jenkins & Eggert Expires 21 August 2025 [Page 1]
57+58+Internet-Draft Further IMAP/JMAP keywords & attributes February 2025
59+60+61+ This document is subject to BCP 78 and the IETF Trust's Legal
62+ Provisions Relating to IETF Documents (https://trustee.ietf.org/
63+ license-info) in effect on the date of publication of this document.
64+ Please review these documents carefully, as they describe your rights
65+ and restrictions with respect to this document. Code Components
66+ extracted from this document must include Revised BSD License text as
67+ described in Section 4.e of the Trust Legal Provisions and are
68+ provided without warranty as described in the Revised BSD License.
69+70+Table of Contents
71+72+ 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3
73+ 2. Requirements Language . . . . . . . . . . . . . . . . . . . . 4
74+ 3. Flag Colors . . . . . . . . . . . . . . . . . . . . . . . . . 4
75+ 3.1. Definition of the MailFlagBit Message Keyword . . . . . . 4
76+ 3.2. Implementation Notes . . . . . . . . . . . . . . . . . . 5
77+ 4. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 5
78+ 4.1. IMAP/JMAP Keyword Registrations . . . . . . . . . . . . . 5
79+ 4.1.1. $notify keyword registration . . . . . . . . . . . . 5
80+ 4.1.2. $muted keyword registration . . . . . . . . . . . . . 6
81+ 4.1.3. $followed keyword registration . . . . . . . . . . . 7
82+ 4.1.4. $memo keyword registration . . . . . . . . . . . . . 7
83+ 4.1.5. $hasmemo keyword registration . . . . . . . . . . . . 8
84+ 4.1.6. Attachment Detection . . . . . . . . . . . . . . . . 8
85+ 4.1.7. $autosent keyword registration . . . . . . . . . . . 9
86+ 4.1.8. $unsubscribed keyword registration . . . . . . . . . 10
87+ 4.1.9. $canunsubscribe keyword registration . . . . . . . . 10
88+ 4.1.10. $imported keyword registration . . . . . . . . . . . 11
89+ 4.1.11. $istrusted keyword registration . . . . . . . . . . . 11
90+ 4.1.12. $maskedemail keyword registration . . . . . . . . . . 12
91+ 4.1.13. $new keyword registration . . . . . . . . . . . . . . 12
92+ 4.1.14. $MailFlagBit0 keyword registration . . . . . . . . . 13
93+ 4.1.15. $MailFlagBit1 keyword registration . . . . . . . . . 13
94+ 4.1.16. $MailFlagBit2 keyword registration . . . . . . . . . 13
95+ 4.2. IMAP Mailbox Name Attributes Registrations . . . . . . . 14
96+ 4.2.1. Snoozed mailbox name attribute registration . . . . . 14
97+ 4.2.2. Scheduled mailbox name attribute registration . . . . 14
98+ 4.2.3. Memos mailbox name attribute registration . . . . . . 14
99+ 5. Security Considerations . . . . . . . . . . . . . . . . . . . 15
100+ 6. References . . . . . . . . . . . . . . . . . . . . . . . . . 15
101+ 6.1. Normative References . . . . . . . . . . . . . . . . . . 15
102+ Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 15
103+104+105+106+107+108+109+110+111+112+Jenkins & Eggert Expires 21 August 2025 [Page 2]
113+114+Internet-Draft Further IMAP/JMAP keywords & attributes February 2025
115+116+117+1. Introduction
118+119+ The Internet Message Access Protocol (IMAP) specification [RFC9051]
120+ defines the use of message keywords, and an "IMAP Keywords" registry
121+ is created in [RFC5788]. Similarly [RFC8457] creates an "IMAP
122+ Mailbox Name Attributes Registry".
123+124+ This document does the following:
125+126+ * Defines 16 message keywords
127+128+ - $notify
129+130+ - $muted
131+132+ - $followed
133+134+ - $memo
135+136+ - $hasmemo
137+138+ - $hasattachment
139+140+ - $hasnoattachment
141+142+ - $autosent
143+144+ - $unsubscribed
145+146+ - $canunsubscribe
147+148+ - $imported
149+150+ - $istrusted
151+152+ - $maskedemail
153+154+ - $new
155+156+ - $MailFlagBit0
157+158+ - $MailFlagBit1
159+160+ - $MailFlagBit2
161+162+ * Defines 3 mailbox name attributes
163+164+ - Snoozed
165+166+167+168+Jenkins & Eggert Expires 21 August 2025 [Page 3]
169+170+Internet-Draft Further IMAP/JMAP keywords & attributes February 2025
171+172+173+ - Scheduled
174+175+ - Memos
176+177+ * Registers these in the "IMAP Keywords" registry and "IMAP Mailbox
178+ Name Attributes" registry respectively.
179+180+2. Requirements Language
181+182+ The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
183+ "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and
184+ "OPTIONAL" in this document are to be interpreted as described in BCP
185+ 14 [RFC2119] [RFC8174] when, and only when, they appear in all
186+ capitals, as shown here.
187+188+3. Flag Colors
189+190+ The Internet Message Access Protocol (IMAP) specification [RFC9051]
191+ defines a \Flagged system flag to mark a message for urgent/special
192+ attention. The new keywords defined in Sections 4.1.14, 4.1.15, and
193+ 4.1.16 allow such a flagged message to have that flag be of one of 7
194+ colors.
195+196+3.1. Definition of the MailFlagBit Message Keyword
197+198+ The 3 flag color keywords $MailFlagBit0, $MailFlagBit1, and
199+ $MailFlagBit2 make up a bit pattern that define the color of the flag
200+ as such:
201+202+ +=======+=======+=======+========+
203+ | Bit 0 | Bit 1 | Bit 2 | Color |
204+ +=======+=======+=======+========+
205+ | 0 | 0 | 0 | red |
206+ +-------+-------+-------+--------+
207+ | 1 | 0 | 0 | orange |
208+ +-------+-------+-------+--------+
209+ | 0 | 1 | 0 | yellow |
210+ +-------+-------+-------+--------+
211+ | 1 | 1 | 1 | green |
212+ +-------+-------+-------+--------+
213+ | 0 | 0 | 1 | blue |
214+ +-------+-------+-------+--------+
215+ | 1 | 0 | 1 | purple |
216+ +-------+-------+-------+--------+
217+ | 0 | 1 | 1 | gray |
218+ +-------+-------+-------+--------+
219+220+ Table 1: Flag Colors
221+222+223+224+Jenkins & Eggert Expires 21 August 2025 [Page 4]
225+226+Internet-Draft Further IMAP/JMAP keywords & attributes February 2025
227+228+229+ These flags SHOULD be ignored if the \Flagged system flag is not set.
230+ If the \Flagged system flag is set, the flagged status MAY be
231+ displayed to the user in the color corresponding to the combination
232+ of the 3 flag color keywords.
233+234+3.2. Implementation Notes
235+236+ A mail client that is aware of these flag color keywords SHOULD clear
237+ all 3 flag color keywords when the user unflags the message, i.e.
238+ when unsetting the \Flagged system flag, all 3 flag color keywords
239+ SHOULD also be unset.
240+241+ A mail client SHOULD NOT set any of these flags unless the \Flagged
242+ system flag is already set or is being set.
243+244+ Servers MAY unset these flag color keywords when a client unsets the
245+ \Flagged system flag.
246+247+4. IANA Considerations
248+249+ 3 IMAP/JMAP keywords are registered in the IMAP/JMAP keywords
250+ registry, as established in RFC5788.
251+252+4.1. IMAP/JMAP Keyword Registrations
253+254+4.1.1. $notify keyword registration
255+256+ IMAP/JMAP keyword name: $notify
257+ Purpose: Indicate to the client that a notification should be shown
258+ for this message.
259+ Private or Shared on a server: SHARED
260+ Is it an advisory keyword or may it cause an automatic action: This
261+ keyword can cause automatic action. On supporting clients, when a
262+ new message is added to the mailstore with this keyword, the
263+ client should show the user a notification.
264+ Mail clients commonly show notifications for new mail, but often
265+ the only option is to show a notification for every message that
266+ arrives in the inbox. This keyword allows the user to create
267+ rules (or the server to automatically determine) specific messages
268+ that should show a notification.
269+ Notifications for these messages may be in addition to
270+ notifications for messages matching other criteria, according to
271+ user preference set on the client.
272+ When/by whom the keyword is set/cleared: This keyword is set by a
273+274+275+276+277+278+279+280+Jenkins & Eggert Expires 21 August 2025 [Page 5]
281+282+Internet-Draft Further IMAP/JMAP keywords & attributes February 2025
283+284+285+ server on delivery when a message meets criteria such that the
286+ user should be shown a notification. It may be cleared by a
287+ client when the user opens, archives, or otherwise interacts with
288+ the message. Other clients connected to the same account may
289+ choose to automatically close the notification if the flag is
290+ cleared.
291+ Related keywords: None
292+ Related IMAP capabilities: None
293+ Security considerations: None
294+ Published specification: This document
295+ Intended usage: COMMON
296+ Scope: BOTH
297+ Owner/Change controller: IESG
298+299+4.1.2. $muted keyword registration
300+301+ IMAP/JMAP keyword name: $muted
302+ Purpose: Indicate to the server that the user is not interested in
303+ future replies to a particular thread.
304+ Private or Shared on a server: SHARED
305+ Is it an advisory keyword or may it cause an automatic action: This
306+ keyword can cause automatic action. On supporting servers, when a
307+ new message arrives that is in the same thread as a message with
308+ this keyword the server may automatically process it in some way
309+ to deprioritise it for the user, for example by moving it to the
310+ archive or trash, or marking it read. The exact action, whether
311+ this is customisable by the user, and interaction with user rules
312+ is vendor specific.
313+ A message is defined to be in the same thread as another if the
314+ server assigns them both the same thread id, as defined in
315+ [RFC8474] Section 5.2 for IMAP or [RFC8621], Section 3 for JMAP.
316+ When/by whom the keyword is set/cleared: This keyword is set by a
317+ client when the user indicates they wish to mute or unmute a
318+ thread. When unmuting a thread, the client must remove the
319+ keyword from every message in the thread that has it.
320+ Related keywords: Mutually exclusive with $followed. If both are
321+ specified on a thread, servers MUST behave as though only
322+ $followed were set.
323+ Related IMAP capabilities: None
324+ Security considerations: Muting a thread can mean a user won't see a
325+ reply. If someone compromises a user's account, they may mute
326+ threads where they don't want the user to see the reply, for
327+ example when sending phishing to the user's contacts. There are
328+ many other ways an attacker with access to the user's mailbox can
329+ also achieve this however, so this is not greatly increasing the
330+ attack surface.
331+ Published specification: This document
332+ Intended usage: COMMON
333+334+335+336+Jenkins & Eggert Expires 21 August 2025 [Page 6]
337+338+Internet-Draft Further IMAP/JMAP keywords & attributes February 2025
339+340+341+ Scope: BOTH
342+ Owner/Change controller: IESG
343+344+4.1.3. $followed keyword registration
345+346+ IMAP/JMAP keyword name: $followed
347+ Purpose: Indicate to the server that the user is particularly
348+ interested in future replies to a particular thread.
349+ Private or Shared on a server: SHARED
350+ Is it an advisory keyword or may it cause an automatic action: This
351+ keyword can cause automatic action. On supporting servers, when a
352+ new message arrives that is in the same thread as a message with
353+ this keyword the server may automatically process it in some way
354+ to prioritise it for the user, for example by ignoring rules that
355+ would make it skip the inbox, or automatically adding the $notify
356+ keyword. The exact action, whether this is customisable by the
357+ user, and interaction with user rules is vendor specific.
358+ A message is defined to be in the same thread as another if the
359+ server assigns them both the same thread id, as defined in
360+ [RFC8474] Section 5.2 for IMAP or [RFC8621], Section 3 for JMAP.
361+ When/by whom the keyword is set/cleared: This keyword is set by a
362+ client when the user indicates they wish to follow or unfollow a
363+ thread. When unfollowing a thread, the client must remove the
364+ keyword from every message in the thread that has it.
365+ Related keywords: Mutually exclusive with $muted. If both are
366+ specified on a thread, servers MUST behave as though only
367+ $followed were set.
368+ Related IMAP capabilities: None
369+ Security considerations: None
370+ Published specification: This document
371+ Intended usage: COMMON
372+ Scope: BOTH
373+ Owner/Change controller: IESG
374+375+4.1.4. $memo keyword registration
376+377+ IMAP/JMAP keyword name: $memo
378+ Purpose: Indicate to the client that a message is a note-to-self
379+ from the user regarding another message in the same thread.
380+ Private or Shared on a server: SHARED
381+ Is it an advisory keyword or may it cause an automatic action: This
382+ keyword is advisory.
383+ When/by whom the keyword is set/cleared: This keyword is set by a
384+ client when creating such a message. The message should otherwise
385+ be contructed like a reply to the message to which this memo is
386+ attached (i.e. appropriate Subject and Reply-To headers set). In
387+ supporting clients, messages with this flag may be presented
388+ differently to the user, attached to the message the memo is
389+390+391+392+Jenkins & Eggert Expires 21 August 2025 [Page 7]
393+394+Internet-Draft Further IMAP/JMAP keywords & attributes February 2025
395+396+397+ commenting on, and may offer the user the ability to edit or
398+ delete the memo. (As messages are immutable, editing requires
399+ replacing the message.)
400+ Related keywords: The $hasmemo keyword should be set/cleared at the
401+ same time.
402+ Related IMAP capabilities: None
403+ Security considerations: None
404+ Published specification: This document
405+ Intended usage: COMMON
406+ Scope: BOTH
407+ Owner/Change controller: IESG
408+409+4.1.5. $hasmemo keyword registration
410+411+ IMAP/JMAP keyword name: $hasmemo
412+ Purpose: Indicate to the client that a message has an associated
413+ memo with the $memo keyword.
414+ Private or Shared on a server: SHARED
415+ Is it an advisory keyword or may it cause an automatic action: This
416+ keyword is advisory.
417+ When/by whom the keyword is set/cleared: This keyword is set by a
418+ client when creating a memo. The memo gets the $memo keyword, the
419+ message it is a note for gets the $hasmemo keyword. This keyword
420+ can help in searching for messages with memos, or deciding whether
421+ to fetch the whole thread to look for memos when loading a
422+ mailbox.
423+ Related keywords: A message with the $memo keyword should be
424+ created/destroyed at the same time.
425+ Related IMAP capabilities: None
426+ Security considerations: None
427+ Published specification: This document
428+ Intended usage: COMMON
429+ Scope: BOTH
430+ Owner/Change controller: IESG
431+432+4.1.6. Attachment Detection
433+434+ The $hasattachment and $hasnoattachment are mutually exclusive. A
435+ message SHOULD NOT contain both keywords.
436+437+4.1.6.1. $hasattachment keyword registration
438+439+ IMAP/JMAP keyword name: $hasattachment
440+ Purpose: Indicate to the client that a message has an attachment.
441+ Private or Shared on a server: SHARED
442+ Is it an advisory keyword or may it cause an automatic action: This
443+ keyword is advisory.
444+ When/by whom the keyword is set/cleared: This keyword is set by a
445+446+447+448+Jenkins & Eggert Expires 21 August 2025 [Page 8]
449+450+Internet-Draft Further IMAP/JMAP keywords & attributes February 2025
451+452+453+ server on messages it determines have an attachment. This can
454+ help mailbox clients indicate this to the user without having to
455+ fetch the full message body structure. Over JMAP, the
456+ "hasAttachment" Email property should indicate the same value.
457+ Related keywords: $hasnoattachment
458+ Related IMAP capabilities: None
459+ Security considerations: None
460+ Published specification: This document
461+ Intended usage: COMMON
462+ Scope: BOTH
463+ Owner/Change controller: IESG
464+465+4.1.6.2. $hasnoattachment keyword registration
466+467+ IMAP/JMAP keyword name: $hasnoattachment
468+ Purpose: Indicate to the client that a message does not have an
469+ attachment.
470+ Private or Shared on a server: SHARED
471+ Is it an advisory keyword or may it cause an automatic action: This
472+ keyword is advisory.
473+ When/by whom the keyword is set/cleared: This keyword is set by a
474+ server on messages it determines does NOT have an attachment.
475+ Over JMAP, the "hasNoAttachment" Email property should indicate
476+ the same value. This keyword is needed in addition to the
477+ $hasattachment keyword, as a client cannot otherwise determine
478+ whether the server has processed the message for the presence of
479+ an attachment. In other words, the absence of the $hasattachment
480+ keyword for a message does not tell a client whether the message
481+ actually contains an attachment, as the client has no information
482+ on whether the server has processed the message.
483+ Related keywords: None
484+ Related IMAP capabilities: None
485+ Security considerations: None
486+ Published specification: This document
487+ Intended usage: COMMON
488+ Scope: BOTH
489+ Owner/Change controller: IESG
490+491+4.1.7. $autosent keyword registration
492+493+ IMAP/JMAP keyword name: $autosent
494+ Purpose: Indicate to the client that a message was sent
495+ automatically as a response due to a user rule or setting.
496+ Private or Shared on a server: SHARED
497+ Is it an advisory keyword or may it cause an automatic action: This
498+ keyword is advisory.
499+ When/by whom the keyword is set/cleared: This keyword is set by a
500+501+502+503+504+Jenkins & Eggert Expires 21 August 2025 [Page 9]
505+506+Internet-Draft Further IMAP/JMAP keywords & attributes February 2025
507+508+509+ server on the user's copy of their vacation response and other
510+ automated messages sent on behalf of the user. Clients may use
511+ this to indicate to the user that this message was sent
512+ automatically, as if they have forgotten the rule or vacation
513+ response is set up they may be surprised to see it among their
514+ sent items.
515+ Related keywords: None
516+ Related IMAP capabilities: None
517+ Security considerations: None
518+ Published specification: This document
519+ Intended usage: COMMON
520+ Scope: BOTH
521+ Owner/Change controller: IESG
522+523+4.1.8. $unsubscribed keyword registration
524+525+ IMAP/JMAP keyword name: $unsubscribed
526+ Purpose: Indicate to the client that it has unsubscribed from the
527+ thread this message is on.
528+ Private or Shared on a server: SHARED
529+ Is it an advisory keyword or may it cause an automatic action: This
530+ keyword is advisory.
531+ When/by whom the keyword is set/cleared: This keyword is set by a
532+ client on a message after attempting to unsubscribe from the
533+ mailing list this message came from (e.g., after attempting
534+ RFC8058 one-click List-Unsubscribe). It allows clients to remind
535+ the user that they have unsubscribed if they open the message
536+ again.
537+ Related keywords: None
538+ Related IMAP capabilities: None
539+ Security considerations: None
540+ Published specification: This document
541+ Intended usage: COMMON
542+ Scope: BOTH
543+ Owner/Change controller: IESG
544+545+4.1.9. $canunsubscribe keyword registration
546+547+ IMAP/JMAP keyword name: $canunsubscribe
548+ Purpose: Indicate to the client that this message has an
549+ RFC8058-compliant List-Unsubscribe header.
550+ Private or Shared on a server: SHARED
551+ Is it an advisory keyword or may it cause an automatic action: This
552+ keyword is advisory.
553+ When/by whom the keyword is set/cleared: This keyword is set by a
554+555+556+557+558+559+560+Jenkins & Eggert Expires 21 August 2025 [Page 10]
561+562+Internet-Draft Further IMAP/JMAP keywords & attributes February 2025
563+564+565+ server on messages with an RFC8058-compliant List-Unsubscribe
566+ header. It may only do so if the message passes vendor-specific
567+ reputation checks. It is intended to indicate to clients that
568+ they may be able to do a one-click unsubscribe, without them
569+ having to fetch the List-Unsubscribe header to determine themself.
570+ Related keywords: None
571+ Related IMAP capabilities: None
572+ Security considerations: None
573+ Published specification: This document
574+ Intended usage: COMMON
575+ Scope: BOTH
576+ Owner/Change controller: IESG
577+578+4.1.10. $imported keyword registration
579+580+ IMAP/JMAP keyword name: $imported
581+ Purpose: Indicate to the client that this message was imported from
582+ another mailbox.
583+ Private or Shared on a server: SHARED
584+ Is it an advisory keyword or may it cause an automatic action: This
585+ keyword is advisory.
586+ When/by whom the keyword is set/cleared: This keyword is set by a
587+ server on messages in imports from another mailbox.
588+ Related keywords: None
589+ Related IMAP capabilities: None
590+ Security considerations: None
591+ Published specification: This document
592+ Intended usage: COMMON
593+ Scope: BOTH
594+ Owner/Change controller: IESG
595+596+4.1.11. $istrusted keyword registration
597+598+ IMAP/JMAP keyword name: $istrusted
599+ Purpose: Indicate to the client that the authenticity of the from
600+ name and email address have been verified with complete confidence
601+ by the server.
602+ Private or Shared on a server: SHARED
603+ Is it an advisory keyword or may it cause an automatic action: This
604+ keyword is advisory. Clients may show a verification mark (often
605+ a tick icon) on messages with this keyword to indicate their
606+ trusted status to the user.
607+ When/by whom the keyword is set/cleared: This keyword is set by a
608+ server on messages it delivers where it wishes to confirm to the
609+ user that this is a legitimate email they can trust. It is
610+ usually only used for the mailbox provider's own messages to the
611+ customer, where they can know with absolute certainty that the
612+ friendly from name and email address are legitimate.
613+614+615+616+Jenkins & Eggert Expires 21 August 2025 [Page 11]
617+618+Internet-Draft Further IMAP/JMAP keywords & attributes February 2025
619+620+621+ Related keywords: None
622+ Related IMAP capabilities: None
623+ Security considerations: Servers should make sure this keyword is
624+ only set for messages that really are trusted!
625+ Published specification: This document
626+ Intended usage: COMMON
627+ Scope: BOTH
628+ Owner/Change controller: IESG
629+630+4.1.12. $maskedemail keyword registration
631+632+ IMAP/JMAP keyword name: $maskedemail
633+ Purpose: Indicate to the client that the message was received via an
634+ alias created for an individual sender.
635+ Private or Shared on a server: SHARED
636+ Is it an advisory keyword or may it cause an automatic action: This
637+ keyword is advisory. Clients may show an icon to indicate to the
638+ user this was received via a masked email address - an alias
639+ created for a specific sender to hide the user's real email
640+ address.
641+ When/by whom the keyword is set/cleared: This keyword is set by a
642+ server on messages it delivers that arrived via such an alias.
643+ Related keywords: None
644+ Related IMAP capabilities: None
645+ Security considerations: None
646+ Published specification: This document
647+ Intended usage: LIMITED
648+ Scope: BOTH
649+ Owner/Change controller: IESG
650+651+4.1.13. $new keyword registration
652+653+ IMAP/JMAP keyword name: $new
654+ Purpose: Indicate to the client that a message should be made more
655+ prominent to the user due to a recent action.
656+ Private or Shared on a server: SHARED
657+ Is it an advisory keyword or may it cause an automatic action: This
658+ keyword is advisory. Clients may show the status of the message.
659+ When/by whom the keyword is set/cleared: This keyword is set by a
660+ server on messages after awakening them from snooze. Clients
661+ should clear the keyword when the message is opened.
662+ Related keywords: None
663+ Related IMAP capabilities: None
664+ Security considerations: None
665+ Published specification: This document
666+ Intended usage: LIMITED
667+ Scope: BOTH
668+ Owner/Change controller: IESG
669+670+671+672+Jenkins & Eggert Expires 21 August 2025 [Page 12]
673+674+Internet-Draft Further IMAP/JMAP keywords & attributes February 2025
675+676+677+4.1.14. $MailFlagBit0 keyword registration
678+679+ IMAP/JMAP keyword name: $MailFlagBit0
680+ Purpose: 0 bit part of a 3-bit bitmask that defines the color of the
681+ flag when the has the system flag \Flagged set. See Section 3 for
682+ details.
683+ Private or Shared on a server: SHARED
684+ Is it an advisory keyword or may it cause an automatic action: No
685+ When/by whom the keyword is set/cleared: This keyword is set by a
686+ client as the result of a user action to "flag" a message for
687+ urgent/special attention.
688+ Related keywords: $MailFlagBit1, $MailFlagBit2
689+ Related IMAP capabilities: None
690+ Security considerations: None
691+ Published specification: This document
692+ Intended usage: COMMON
693+ Owner/Change controller: IESG
694+695+4.1.15. $MailFlagBit1 keyword registration
696+697+ IMAP/JMAP keyword name: $MailFlagBit1
698+ Purpose: 0 bit part of a 3-bit bitmask that defines the color of the
699+ flag when the has the system flag \Flagged set. See Section 3 for
700+ details.
701+ Private or Shared on a server: SHARED
702+ Is it an advisory keyword or may it cause an automatic action: No
703+ When/by whom the keyword is set/cleared: This keyword is set by a
704+ client as the result of a user action to "flag" a message for
705+ urgent/special attention.
706+ Related keywords: $MailFlagBit0, $MailFlagBit2
707+ Related IMAP capabilities: None
708+ Security considerations: None
709+ Published specification: This document
710+ Intended usage: COMMON
711+ Owner/Change controller: IESG
712+713+4.1.16. $MailFlagBit2 keyword registration
714+715+ IMAP/JMAP keyword name: $MailFlagBit2
716+ Purpose: 0 bit part of a 3-bit bitmask that defines the color of the
717+ flag when the has the system flag \Flagged set. See Section 3 for
718+ details.
719+ Private or Shared on a server: SHARED
720+ Is it an advisory keyword or may it cause an automatic action: No
721+ When/by whom the keyword is set/cleared: This keyword is set by a
722+ client as the result of a user action to "flag" a message for
723+ urgent/special attention.
724+ Related keywords: $MailFlagBit0, $MailFlagBit1
725+726+727+728+Jenkins & Eggert Expires 21 August 2025 [Page 13]
729+730+Internet-Draft Further IMAP/JMAP keywords & attributes February 2025
731+732+733+ Related IMAP capabilities: None
734+ Security considerations: None
735+ Published specification: This document
736+ Intended usage: COMMON
737+ Owner/Change controller: IESG
738+739+4.2. IMAP Mailbox Name Attributes Registrations
740+741+ This section lists mailbox name attributes to be registered with the
742+ "IMAP Mailbox Name Attributes" created with [RFC8457].
743+744+ Note that none of the attribute names in this seciton have an implied
745+ backslash. This sets them apart from those specified in Section 2 of
746+ [RFC6154].
747+748+4.2.1. Snoozed mailbox name attribute registration
749+750+ Attribute Name: Snoozed
751+ Description: Messages that have been snoozed are moved to this
752+ mailbox until the "awaken" time, when they are moved out of it
753+ again automatically by the server.
754+ Reference: This document.
755+ Usage Notes: Snooze functionality is common among services but not
756+ yet standardised. This attribute marks the mailbox where snoozed
757+ messages may be found, but does not on its own provide a way for
758+ clients to snooze messages.
759+760+4.2.2. Scheduled mailbox name attribute registration
761+762+ Attribute Name: Scheduled
763+ Description: Messages that have been scheduled to send at a later
764+ time. Once the server has sent them at the scheduled time, they
765+ will automatically be deleted or moved from this mailbox by the
766+ server (probably to the \Sent mailbox).
767+ Reference: This document.
768+ Usage Notes: Scheduled sending functionality is common among
769+ services but not yet standardised. This attribute marks the
770+ mailbox where scheduled messages may be found, but does not on its
771+ own provide a way for clients to schedule messages for sending.
772+773+4.2.3. Memos mailbox name attribute registration
774+775+ Attribute Name: Memos
776+ Description: Messages that have the $memo keyword. Clients creating
777+ memos are recommended to store them in this mailbox. This allows
778+ them to more easily be hidden from the user as "messages", and
779+ presented only as memos instead.
780+ Reference: This document.
781+782+783+784+Jenkins & Eggert Expires 21 August 2025 [Page 14]
785+786+Internet-Draft Further IMAP/JMAP keywords & attributes February 2025
787+788+789+ Usage Notes: None.
790+791+5. Security Considerations
792+793+ This document should not affect the security of the Internet.
794+795+6. References
796+797+6.1. Normative References
798+799+ [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
800+ Requirement Levels", BCP 14, RFC 2119,
801+ DOI 10.17487/RFC2119, March 1997,
802+ <https://www.rfc-editor.org/info/rfc2119>.
803+804+ [RFC6154] Leiba, B. and J. Nicolson, "IMAP LIST Extension for
805+ Special-Use Mailboxes", RFC 6154, DOI 10.17487/RFC6154,
806+ March 2011, <https://www.rfc-editor.org/info/rfc6154>.
807+808+ [RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC
809+ 2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174,
810+ May 2017, <https://www.rfc-editor.org/info/rfc8174>.
811+812+ [RFC8457] Leiba, B., Ed., "IMAP "$Important" Keyword and
813+ "\Important" Special-Use Attribute", RFC 8457,
814+ DOI 10.17487/RFC8457, September 2018,
815+ <https://www.rfc-editor.org/info/rfc8457>.
816+817+ [RFC8474] Gondwana, B., Ed., "IMAP Extension for Object
818+ Identifiers", RFC 8474, DOI 10.17487/RFC8474, September
819+ 2018, <https://www.rfc-editor.org/info/rfc8474>.
820+821+ [RFC8621] Jenkins, N. and C. Newman, "The JSON Meta Application
822+ Protocol (JMAP) for Mail", RFC 8621, DOI 10.17487/RFC8621,
823+ August 2019, <https://www.rfc-editor.org/info/rfc8621>.
824+825+ [RFC9051] Melnikov, A., Ed. and B. Leiba, Ed., "Internet Message
826+ Access Protocol (IMAP) - Version 4rev2", RFC 9051,
827+ DOI 10.17487/RFC9051, August 2021,
828+ <https://www.rfc-editor.org/info/rfc9051>.
829+830+ [RFC5788] Melnikov, A. and D. Cridland, "IMAP4 Keyword Registry",
831+ RFC 5788, DOI 10.17487/RFC5788, March 2010,
832+ <https://www.rfc-editor.org/info/rfc5788>.
833+834+Authors' Addresses
835+836+837+838+839+840+Jenkins & Eggert Expires 21 August 2025 [Page 15]
841+842+Internet-Draft Further IMAP/JMAP keywords & attributes February 2025
843+844+845+ Neil Jenkins (editor)
846+ Fastmail
847+ PO Box 234, Collins St West
848+ Melbourne VIC 8007
849+ Australia
850+ Email: neilj@fastmailteam.com
851+ URI: https://www.fastmail.com
852+853+854+ Daniel Eggert (editor)
855+ Apple Inc
856+ One Apple Park Way
857+ Cupertino, CA 95014
858+ United States of America
859+ Email: deggert@apple.com
860+ URI: https://www.apple.com
861+862+863+864+865+866+867+868+869+870+871+872+873+874+875+876+877+878+879+880+881+882+883+884+885+886+887+888+889+890+891+892+893+894+895+896+Jenkins & Eggert Expires 21 August 2025 [Page 16]