Varies by inflight entertainment system. CCS on Panasonic quit almost two years ago, at least on 767-300s. Company email used to work too. Think it is still no-op.

On the other hand, I was non-revving on a 737 earlier this month, and the Messages app (green icon) started giving messages...it never used to work in flight. I think the 737s use Indigo, but not sure.