User can also use Mandrill for Transactional Emails by integrating with Mailchimp.
Mandrill is a transactional email API for MailChimp users. It’s reliable, powerful, and ideal for sending data-driven emails, including targeted e-commerce and personalized one-to-one messages,automated transactional emails.
Now let's see how to access Mandrill through Mailchimp
Create a API Key
Next, add your domain and verify along with SPF and DKIM settings.
Login to your hosting server
Click on Domain Panel and go to DNS Zone Editor
Add on your basic DNS records of SPF and DKIM settings from Mandrill.
Now you can see your Test DNS record is verified and valid in Mandrillr