Mailchimp: Set up transactional email (API / SMTP)

2 walk-throughs of this task.

1. 4:020:39Generate API Keys for Transactional EmailHow to create and secure a new API key in the settings menu to connect your website or integration to Mailchimp Transactional.@mailchimp
2. 4:541:15Using Test Mode and Test API KeysDemonstrates how to create a Test API Key and toggle 'Test Mode' to simulate bounces and spam complaints without affecting account reputation.@mailchimp