Cakephp3 email config issue

we currently have a fairly simple cakephp application that manges our deliveries, one of the main things it does is send out out to the customer time slots by SMS this all works well however we also want to tbe able to Email the details to the customer but seem to be struggling with getting the emails sent via cakephp SMTP server

what i need is for someone to help us with the app config file if i supply the SMTP server details