I'm trying to find a lightweight player application to open audio or video email attachments with under Linux.

Ideally, it would just show a compact GUI controller for audio (no need for album art if any), and it'd start playing automatically. If it launches fast enough it could also exit after playback.

Ideally, this could all be configured via a config file rather than by having to enter a string of command line arguments via the helper process configuration interface of my email client.

I've tried mpv, but it seems impossible to configure it to satisfaction, sadly.