Issue 14: Interface with email clients

It would be extremely useful to be able to start an email client on a specific message (found as a search hit). Unfortunately there does not seem to be an easy way to do this.

Need to look closer at each of the major mail clients and see if there is a way for each, maybe taking a hint from the beagle backends.

After a few years contemplating this, it appears that no good solution exists. We have partials for a few of the email clients.