Mailhog is an optional container that can be enabled for your project. You can do this by running
tok config-set services mailhog enabled true or adding the following YAML to your .tok/config.yml file inside your site's repository:
services: mailhog: enabled: true
After adding this configuration you need to run
tok up again to have Mailhog initialised. You can then access Mailhog using your browser by running
tok open mailhog.
The mailhog service is now available to your Drupal site on address: mailhog:1025 . You can use Mailhog to send SMTP messages and test that they were received by the server, but without actually sending the email to the recipients.