By default, Mailcoach sends all mails using the default mailer of your Laravel app. In the mailcoach.php config file, you can override this.
At the time of creating your EmailList, the transactional_mailer and campaign_mailer attributes will be set based on your configuration settings. Any future change in your configuration settings will not automatically apply to the EmailList.
You can also override the mailer to be used on the list level by updating the campaign_mailer attribute with the mailer to be used. Confirmation and welcome mails will be sent using the mailer specified in transactional_mailer.