Hey James,
Thank you for reaching out to us!
You can customize ticket emails by overriding the default template or by using the filters we have available. You will find the original template for the email on:
event-tickets/src/views/tickets/email.php
You can modify/override it by creating a file with your own customization at [your-theme]/tribe-events/tickets/email.php
I hope this helps! If you have any other questions at all please feel free to let me know and I’d be happy to help as best I can!
Cheers,
Patricia