Sieve Email Filtering: Imap4flags Extension
RFC 5232

Received changes through RFC Editor sync (changed abstract to 'Recent discussions have shown that it is desirable to set different IMAP (RFC 3501) flags on message delivery. This can be done, for example, by a Sieve interpreter that works as a part of a Mail Delivery Agent.

This document describes an extension to the Sieve mail filtering language for setting IMAP flags. The extension allows setting of both IMAP system flags and IMAP keywords. [STANDARDS-TRACK]')