RFC7162 (2014): CONDSTORE (recommended by IMAP4rev2) #106

Before CONDSTORE can be implemented, RFC4466 extensions should be generally supported:

• RFC4466 (2006): Collected Extensions to IMAP4 ABNF #35

CONDSTORE makes the following changes to the IMAP4 protocol (from the list at the top of RFC7162 3.1):

• adds the UNCHANGEDSINCE STORE modifier.
  Add unchangedsince kwarg to #store/#uid_store (RFC7162, CONDSTORE) #237
• adds the MODIFIED response code that is used with an OK response to the STORE command. (It can also be used in a NO response.)
• adds a new MODSEQ message data item for use with the FETCH command.
• adds the CHANGEDSINCE FETCH modifier.
  Add changedsince kwarg to #fetch/#uid_fetch (RFC7162, CONDSTORE) #132
• adds a new MODSEQ search criterion.
• extends the syntax of untagged SEARCH and ESEARCH responses to include mod-sequence.
• adds new OK untagged responses (HIGHESTMODSEQ and NOMODSEQ) for the SELECT and EXAMINE commands.
• defines an additional CONDSTORE parameter to SELECT/EXAMINE commands.
  Add condstore kwarg to #select, #examine (RFC7162, CONDSTORE) #122
• adds the HIGHESTMODSEQ status data item to the STATUS command.

Subsections of RFC7162 3.1:

• 3.1.2. New OK Untagged Responses for SELECT and EXAMINE
  • 3.1.2.1. HIGHESTMODSEQ Response Code
  • 3.1.2.2. NOMODSEQ Response Code
• 3.1.3. STORE and UID STORE Commands
  Add unchangedsince kwarg to #store/#uid_store (RFC7162, CONDSTORE) #237
• 3.1.4. FETCH and UID FETCH Commands
  • 3.1.4.1. CHANGEDSINCE FETCH Modifier
    Add changedsince kwarg to #fetch/#uid_fetch (RFC7162, CONDSTORE) #132
  • 3.1.4.2. MODSEQ Message Data Item in FETCH Command
• 3.1.5. MODSEQ Search Criterion in SEARCH
  NOTE: This doesn't require explicit support.
• 3.1.6. Modified SEARCH Untagged Response
• 3.1.7. HIGHESTMODSEQ Status Data Items
• 3.1.8. CONDSTORE Parameter to SELECT and EXAMINE
  Add condstore kwarg to #select, #examine (RFC7162, CONDSTORE) #122
• 3.1.9. Interaction with IMAP SORT and THREAD Extensions
• 3.1.10. Interaction with IMAP ESORT and ESEARCH Extensions