Rather than manually composing a cancellation email through Messages for each booking, you can configure your Access Collins system to automatically send one whenever a booking status is updated to rejected or cancelled.
Once this is set up, you can add a customised message to the automatic message.
You can add text to this message by going to:
Click Settings, then Sites, and select your site.
Click Booking types and select a booking type.
Click Automatic cancellation email.
Enter your text in the box that appears. This can include details such as your responses to customers who you've had no reply from, or cancellation T&C's.
Click Save.