Настройка MailHog в Docksal для Drupal 8

# .docksal/docksal.yml

  cli:
    # Make sure that the cli image is updated.
    image: docksal/cli:2.11-php7.3
    environment:
      - DOCKSAL=true

  mail:
    extends:
      file: ${HOME}/.docksal/stacks/services.yml
      service: mail

В настройках Swift mailer

Transport type: SMTP
SMTP Server: mail
Port: 1025
username: ''
password: ''
encryption: 0