myPlan.cloud only sends important system messages, for example, about what happened on the project the previous day or what approval tasks you have to do. As a project participant, you are obliged to receive these messages, and you can only unsubscribe from them if the administrator has given you the right to unsubscribe. If you think there was a mistake and you shouldn't be receiving such messages, go to the myPlan.cloud interface and contact one of the project administrators.