]> Fastmail Pty Ltd

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Internet-Draft This document extends the IMAP OBJECTID specification in RFC8474 describes persistent identifiers for Mailboxes, Emails, and Threads in email. Some servers may be unable to provide persistent identifiers for one of these but be able to provide data for others, so this extension allows a server to specify that it can provide some reliable ids without needing to implement all data types.

OBJECTID=MAILBOX If a server has the capability OBJECTID=MAILBOX then it supports the objectids for mailboxes described in section 4.

OBJECTID=EMAILID If a server has the capability OBJECTID=EMAILID then it supports the objectids for emails (and optionally threads) described in sections 5 and 6.

Supporting multiple datatypes An implementation which supports both MAILBOXID and EMAILDID SHOULD only issue the capability OBJECTID as defined in . Clients MUST accept any combination of capabilities to decide which requests to send.

IANA considerations IANA is asked to register the capabilities OBJECTID=MAILBOX and OBJECTID=EMAILID with a reference to this document.

Security considerations This document does not introduce any security considerations beyond those described in .

Acknowledgements Daniel Eggert, Ken Murchison, Matt Diephouse, the bar at Melia Castilla in Madrid.

This document updates RFC 3501 (IMAP4rev1) with persistent identifiers on mailboxes and messages to allow clients to more efficiently reuse cached data when resources have changed location on the server.

Changes from Earlier Versions [[This section to be removed by RFC Editor]]

draft-gondwana-imap-objectid-partial Initial version