Find a better name for this

I don't like the name devmail.

I would like to emphasize that this thing keeps your mail only temporarily but all names I can come up with are kind of longish:

* "ephemeral post box"
* "momentary post office"
* 🤔 "brief" of course means "short in time", but it's also Dutch and German for "letter" ...

Suggestions are very welcome!