Internet Assigned Numbers Authority Internet Message Access Protocol (IMAP) Capabilities Registry Last Updated 2024-11-26 Available Formats [IMG] XML [IMG] HTML [IMG] Plain text Registries included below • IMAP Capabilities • IMAP Quota Resource Types IMAP Capabilities Registration Procedure(s) IETF Review Reference [RFC3501][RFC9051] Note Client implementations compliant with [RFC3501] SHOULD NOT require any capability name other than "IMAP4rev1". Client implementations compliant with [RFC9051] SHOULD NOT require any capability name other than "IMAP4rev2", and possibly "STARTTLS" and "LOGINDISABLED" (on a cleartext port). All client implementations MUST ignore any unknown capability names. The prefix "QUOTA=RES-" is reserved per [RFC9208, Section 9.1]. See Section 9.2 of that document for values that follow this prefix. All other capabilities starting with the "QUOTA=" prefix are reserved for future IETF Stream extensions to [RFC9208]. Available Formats [IMG] CSV Capability Name Reference ACL [RFC4314] ANNOTATE-EXPERIMENT-1 [RFC5257] APPENDLIMIT [RFC7889] AUTH= [RFC3501][RFC9051] BINARY [RFC3516] CATENATE [RFC4469] CHILDREN [RFC3348] COMPRESS=DEFLATE [RFC4978] CONDSTORE [RFC7162] CONTEXT=SEARCH [RFC5267] CONTEXT=SORT [RFC5267] CONVERT [RFC5259] CREATE-SPECIAL-USE [RFC6154] ENABLE [RFC5161] ESEARCH [RFC4731] ESORT [RFC5267] FILTERS [RFC5466] I18NLEVEL=1 [RFC5255] I18NLEVEL=2 [RFC5255] ID [RFC2971] IDLE [RFC2177] IMAP4REV1 [RFC3501] IMAP4REV2 [RFC9051] IMAPSIEVE= [RFC6785] INPROGRESS [RFC9585] JMAPACCESS [RFC-ietf-extra-jmapaccess-09] LANGUAGE [RFC5255] LIST-EXTENDED [RFC5258] LIST-METADATA [RFC9590] LIST-MYRIGHTS [RFC8440] LIST-STATUS [RFC5819] LITERAL+ [RFC7888] LITERAL- [RFC7888] LOGIN-REFERRALS [RFC2221] LOGINDISABLED [RFC3501][RFC9051] MAILBOX-REFERRALS [RFC2193] MESSAGELIMIT= [RFC-ietf-extra-imap-messagelimit-10] METADATA [RFC5464] METADATA-SERVER [RFC5464] MOVE [RFC6851] MULTIAPPEND [RFC3502] MULTISEARCH [RFC7377] NAMESPACE [RFC2342] NOTIFY [RFC5465] OBJECTID [RFC8474] PARTIAL [RFC9394] PREVIEW [RFC8970] QRESYNC [RFC7162] QUOTA [RFC9208] QUOTA= [RFC9208] QUOTASET [RFC9208] REPLACE [RFC8508] RIGHTS= [RFC4314] SASL-IR [RFC4959] SAVEDATE [RFC8514] SAVELIMIT= [RFC-ietf-extra-imap-messagelimit-10] SEARCH=FUZZY [RFC6203] SEARCHRES [RFC5182] SORT [RFC5256] SORT=DISPLAY [RFC5957] SPECIAL-USE [RFC6154] STARTTLS [RFC3501][RFC9051] STATUS=SIZE [RFC8438] THREAD [RFC5256] UIDONLY [RFC9586] UIDPLUS [RFC4315] UNAUTHENTICATE [RFC8437] UNSELECT [RFC3691] URL-PARTIAL [RFC5550] URLAUTH [RFC4467] URLAUTH=BINARY [RFC5524][RFC Errata 6214] UTF8=ACCEPT [RFC-ietf-extra-6855bis-04] UTF8=ALL (OBSOLETE) [RFC5738][RFC-ietf-extra-6855bis-04] UTF8=APPEND (OBSOLETE) [RFC5738][RFC-ietf-extra-6855bis-04] UTF8=ONLY [RFC-ietf-extra-6855bis-04] UTF8=USER (OBSOLETE) [RFC5738][RFC-ietf-extra-6855bis-04] WITHIN [RFC5032] IMAP Quota Resource Types Registration Procedure(s) Specification Required Expert(s) Alexey Melnikov, Ken Murchison Reference [RFC9208] Available Formats [IMG] CSV Name of the Quota Description Extra required IMAP Extra optional IMAP Author Change Reference Resource Type commands/responses commands/responses Controller The physical space estimate, in units of DELETED-STORAGE STATUS [RFC9208, STORAGE 1024 octets, of the mailboxes governed request data item and N/A [Alexey_Melnikov] [IESG] Section 5.1] by the quota root. response data item The number of messages stored within the DELETED STATUS request [RFC9208, MESSAGE mailboxes governed by the quota root. data item and response N/A [Alexey_Melnikov] [IESG] Section 5.2] data item MAILBOX The number of mailboxes governed by the N/A N/A [Alexey_Melnikov] [IESG] [RFC9208, quota root. Section 5.3] The maximum size of all annotations ANNOTATION-STORAGE [RFC5257], in units of 1024 octets, N/A N/A [Alexey_Melnikov] [IESG] [RFC9208, associated with all messages in the Section 5.4] mailboxes governed by the quota root. Contact Information ID Name Contact URI Last Updated [Alexey_Melnikov] Alexey Melnikov mailto:alexey.melnikov&isode.com 2021-12-09 [IESG] IESG mailto:iesg&ietf.org 2021-12-09 Licensing Terms