Cannot Send email from On-premise Shared mailbox using 365 Mailbox in Hybrid Environment

Question

Dears

In an hybrid environment when sending an email from On-premise Shared mailbox using 365 Mailbox we receive the following message:

Indice ROP: 4
ROP associato: ropTransportSend (74)
Microsoft.Exchange.Data.Storage.SendAsDeniedException: Can't send message.
 ---> Microsoft.Mapi.MapiExceptionSendAsDenied: MapiExceptionSendAsDenied: TransportSend operation has failed (hr=0x80070005, ec=1244)

It was working since many days ago but suddenly it stopped working.

Are these the commands to enable the possibility to send mail?

Thanks!