Can I email all attendees of an event or purchasers of a bundle?

Absolutely! Head to your "Events" tab then choose to manage a specific event, then go to the "Attendees" tab and look for the "Email all..." button in the top right corner. Click it to compose your message and click 'Send to all' when you're done.

You can also do this for purchasers of bundles you've created - head to the "Bundles" tab then choose to manage a specific bundle, then go to the "Attendees" tab and look for the "Email all..." button in the top right corner. Click it to compose your message and click 'Send to all' when you're done.