Yes, the threads that are deleted from the inboxes that you belong to will be stored in the trash view of the left pane. Only admins can delete the messages permanently from here. You can also restore the messages from here and have them in your inbox again. 

To recover deleted threads,

 1.Login to Zoho TeamInbox.

 2. Navigate to the thread that you like to recover from the trash view.

 2. Click Restore from the top bar. Now the thread will be visible in your inbox again.