Smartsheet assignments to users


I am creating a project plan and assigning users to tasks. Some of the users are internal to my organization, while others are users outside of the organization (client).

I am creating my project plan before I conduct the Project Kickoff meeting with my clients. Will they begin getting email notifications that tasks are being assigned as I complete the project plan? I want to "warn" them that they could be getting emails from Smartsheet ahead of the project kickoff so they're not going "wtf are all these emails"?