JMAP for Sieve

JMAP for Sieve (RFC9661) is an extension to the JMAP protocol that allows users to manage their Sieve scripts using the JMAP API. This extension provides a way for users to upload, delete, and list their Sieve scripts, as well as to set a default script for their account. Support for JMAP for Sieve is enabled by default in Stalwart, and no additional configuration is required. However, it is possible to disable on a per-user basis by disabling the JMAP for Sieve permissions for the user.