By selecting the 'Service' flag in the communication editor this ignores the email preferences set by your customers, such as unsubscribed, and will send to all.
It is important that this flag is only selected when sending the following:
1. Sign-up response for a reward program - When a customer registers for your program they need to be sent an email welcoming them with a barcode. This barcode can then be populated in a mobile app.
3. Service update - any disruption to the service the customer is receiving such as their loyalty card is set to expire or the mechanic is changing.