draft-ietf-jmap-emailpush
JSON Meta Application Protocol (JMAP) Email Delivery Push Notifications
This document specifies an extension to the JSON Meta Application
Protocol (JMAP) that allows clients to receive an object via the JMAP
push channel whenever a new email is delivered that matches a client-
defined filter. The object can also include properties from the
email, to allow a user notification to be displayed without having to
make a further network request.