Email notification can be configured so: none, owners, or all participants of a form are automatically Watching a form. Depending on the setup, users that are Watching will receive emails when a form's status level is changed or if a form is trashed.
As a user viewing a form you will know if you are Watching a form by the glyph beside Edit in the Info box.
If you want to stop Watching a form, click Stop.
If you want to watch a form that you are not automatically watching, click Watch this form.