A system comprising: at least one processor; and memory encoding computer executable instructions that, when executed by the at least one processor, perform a method for sending a notification to an entity, the method comprising: identifying one or more entities associated with a user of a file; assigning , via a notification service, a priority level to each of the one or more entities based on a type of activity of one or more activities associated with the file, wherein the priority level includes at least a highest priority level and a lowest priority level; sending , via the notification service, a notification indicating an occurrence of at least one activity from the one or more activities associated with the file to the entity of the one or more identified entities assigned the highest priority level; determining whether an action receipt has been received for the notification, the action receipt indicating that the notification was acted upon; and when it is determined that the action receipt for the notification has not been received within a time period, sending the notification to an entity of the one or more identified entities assigned a second highest priority level. at least one processor; and memory encoding computer executable instructions that, when executed by the at least one processor, perform a method for sending a notification to an entity, the method comprising: identifying one or more entities associated with a user of a file; assigning , via a notification service, a priority level to each of the one or more entities based on a type of activity of one or more activities associated with the file, wherein the priority level includes at least a highest priority level and a lowest priority level; sending , via the notification service, a notification indicating an occurrence of at least one activity from the one or more activities associated with the file to the entity of the one or more identified entities assigned the highest priority level; determining whether an action receipt has been received for the notification, the action receipt indicating that the notification was acted upon; and when it is determined that the action receipt for the notification has not been received within a time period, sending the notification to an entity of the one or more identified entities assigned a second highest priority level. identifying one or more entities associated with a user of a file; assigning , via a notification service, a priority level to each of the one or more entities based on a type of activity of one or more activities associated with the file, wherein the priority level includes at least a highest priority level and a lowest priority level; sending , via the notification service, a notification indicating an occurrence of at least one activity from the one or more activities associated with the file to the entity of the one or more identified entities assigned the highest priority level; determining whether an action receipt has been received for the notification, the action receipt indicating that the notification was acted upon; and when it is determined that the action receipt for the notification has not been received within a time period, sending the notification to an entity of the one or more identified entities assigned a second highest priority level. <EOS>