Sometimes the automatic posts that are generated by MSCRM can seem unnecessary or clutter your activity feed. For example, do you really want to see every time an opportunity is opened or closed? The answer might be 'yes!' for some of you and 'no, thanks' for others depending on the needs of your organization. If some of the posts seem unnecessary, a system administrator can deactivate the rules that generate them.
Under Settings, go to Activity Feeds Rules. Then you can review all of the rules that are available and activate/deactivate them based on the preferences of your organization.