The email scheduler allows you choose whether to retain a fixed set of filters or not. The “Page Parameters” option highlighted below provides that toggle.
Include page parameters - There are many cases where you want to fix the filter selection per email schedule. For example, I have a email for “West” and another one for “East”, so I want dashboard level region filter to remain fixed.
Do not include page parameters – Other times you might want the flexibility to have the email use the latest default filter selection for a dashboard (ie - this the filter state on the latest saved version of the dashboard).