Why is this conversation not available in my inbox?
Every time a new user is added to a Shared Inbox, we sync the existing conversations with them, except the 'stale' ones.
What are Stale conversations? The ones that have been in a 'Closed' state for more than three months.
Hiver features like 'Notes search' and 'Analytics' will take into consideration all conversations including the stale ones. When you click on a stale conversation that hasn't been synced with your inbox, we show you the message 'This conversation isn't available in your inbox.'
NOTE: Stale conversations do get synced with all users if the state is changed to 'Open' - either by a user or due to a customer reply.