First step is to create a relationship between the two tables. You can add a "hasMany" method for the jobs in the user model to collect all jobs. https://laravel.com/docs/5.5/eloquent-relationships#one-to-many
Second step is to create a scope method inside your jobs model that fetches all jobs for a user for today. https://laravel.com/docs/5.5/eloquent#local-scopes
Third step is to send the mail with the given data.