We want to automate the import from one email service to another example: Mailchimp to Mailpoet or Sendfox to Mailpoet.
The other providers are integrated with a lot of other tools so we use them to get emails from other sources and then add them up to Mailpoet or vice versa.
OR We only use Mailpoet for transactional emails so for newsletter we use other tools example Mailchimp. Automate adding list from Mailpoet to Mailchimp.