This is a list of e-mails that are sent to the customer, the merchant, or both. Some of these messages are sent automatically when events happened which are not configurable within SubscriptionBridge (e.g. a new customer purchases a subscription: you don't control when that happens). Others are sent when certain, “configurable” events happen (e.g. a reminder after a payment failed). These events are configured in the Notification Settings, which are defined at the store level within the SubscriptionBridge Merchant Center.
… where the number of days (“N” and “M”) is defined in the Notification Settings for the store.