Let me preface this with ... I am not a MS Exchange Administrator (I have worked with Lotus Domino/Notes in the past so that's my background). So my terminology might be off.
I want to connect to our MS Exchange servers using EWS. Our company security team is making this rather difficult and doesn't want my service to have "super rights" to be able to write to anyone's calendar. (Fair enough) Therefore my question is ... Is there a role that allows a a super user rights to a person's calendar without being able to look at or modify anything else for that user? Or might there be another way to impersonate the user I need to add a calendar item for.
Goal Clarification:
My goal would to be create a standalone java web service that can be called, by any of our applications. This would be an asynchronous process that would add Meetings to a person's calendar. The problem is authentication. If i have a standalone service I not logged in as anyone. So in order to use EWS I would need to provide some sort of credentials. The user account I would be using would need to be able to touch each user's calendar. Our security team sees this as a risk and would giving my service access to much vital information.
To restate my question: Can my service only have access to a people's calendars? Or does giving my service access to Exchange to change a everyone's calendar, does that also give me access to everything else for that user? (Hopefully this clears the mud.) (This is why I asked the question if there was a role within MS Exchange that would allow for this.)
Again I'm wanting to know from an Administrator/Security point of view. I'll figure out the programming later.