I think it would be useful if you had a dashboard component in Zoho CRM that was specifically for notifications.  This way (for example) a sales manager could post a note to all of the sales representatives, or an executive could post a note to every one in the organization, etc...  Either way, it should (1) appear as a component on the dashboard, (2) keep a scrolling history so that users can see older notes and (3) when creating the note you should be able to select specific users (or a whole group of users) who will be able to see the note.

Thanks -