Marketpress Checkout Process

I’d like more information about the Marketpress checkout process. I have several questions.

What transactional emails are sent during checkout, and at what step of the process are they sent? And are they just plain text emails? What do they look like? If I wanted to use a transactional email service instead (like mandrill) would I be able to turn marketpress’s emails off?

Do the Fedex, ups, or usps apis send shipping and tracking emails to customers?