Bug 31330

Will had some thoughts about this more recently, but here's what the outdated list of use cases in telepathy-spec/doc/request.txt had to say about it:

_`req39`: message-sending UI that doesn't want to know about receiving
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

A UI (perhaps an address book) allows sending one-off messages to contacts,
without entering into a dialogue. If the contact replies, this should be
dispatched as usual.

The UI can't close the channel in a race-free way, and if a message comes
in on the same channel, at that point (only) it needs dispatching to a
handler.

Similarly, imagine a text channel where sending messages is very slow:
we want to be able to close the channel handler (UI) without closing the
channel, and have the channel be re-dispatched only when a message comes in.

Possible solution: for Text channels, somehow arrange for the channel to
be re-dispatched to a "silent" handler; when an incoming message arrives,
the "silent" handler exits (or somehow submits the channel for re-dispatching)
and the CD will re-dispatch to a UI.

Possible solution: closing a Text channel that has pending messages causes
another one to open with the same pending messages

* This is in spec 0.17.9 and Gabble implements it

* Possible infinite-loop situations in Mission Control need investigating