Please note that Planner has its own UserVoice site that its team monitors for feature requests. You can find it here: http://planner.uservoice.com/
An error occurred while saving the commentAaron commented
you can unsubscribe to the plan but leave the notifications turned for the plan and it will not email all parties attached to the plan. It will only email the person that assigned the task when it is complete. people will need to monitor the groups section on outlook like another inbox for when tasks are assigned to them.