2019-08-16: The specifications for JMAP Email have been published by the Internet Engineering Task Force (IETF), marking a big victory for email tools now and in the future.
WikiSuite will add support for JMAP via a combination of contributions to ClearOS, Cyrus, Cypht integrated in Tiki Wiki CMS Groupware and the IETF standardization process. Please see: ClearOS, Cyrus IMAP 3 and JMAP development