Dear Maintainer,

   * What led up to the situation?

I was creating an event in the calendar and adding remote (not on my caldav
server) attendees.

   * What exactly did you do (or not do) that was effective (or
     ineffective)?

The "Notify attendees" checkbox was ticked but greyed out. I understood this to
mean that attendees would be notified and I could not stop it, but they were
not.

   * What was the outcome of this action?

Watching the email logs of both caldav server and client machines showed that
neither sent an email to the remote attendee.

   * What outcome did you expect instead?

I expected the client to send an email, as it does for local calendars.
Ideally, I would like the "Notify attendees" checkbox to be toggle-able.