Just in the process of testing Service Desk email integration and seem to have hit a problem with it not always populating the Request Participants.
I'm expecting this to be populated with any existing users who are included on the original email. This only seems to work if the sender has a Service Desk license assigned to them.
It doesn't populate the field for any emails from 'external' users (ie our customers!), but these will be the bulk of the people contacting our helpdesk.
We need to use automation rules based on this field, so obviously they won't work for most of the emails received...