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IMAP

UNDEFINED-FILTER — UNDEFINED-FILTER

Filter undefined for SEARCH/SORT

Riposte solution

An IMAP SEARCH or SORT filter you used is not defined or supported. Make sure any search criteria or filter syntax is valid for the server. This is uncommon with basic operations, but if you do custom searches via Riposte's IMAP, use standard search keys. Remove or replace the unsupported filter and try again.

Quick facts

Provider
IMAP
Endpoint / surface
IMAP Protocol

Why it happens

[Protocol-level condition per RFC/extension]

How to fix it

[Adjust client behavior per RFC semantics; often retry or change command/parameters]