Docker + configuration SMTP for Mailjet = Time 0ut

Hello,

I try to configure a SMTP mode in nexcloud without success.

I installed nexcloud with docker:

...
  app:  
    image: nextcloud
    container_name: nextcloud
    ports:
      - 8091:80
      - 587:587
    links:
      - db
    volumes:
      - ./data/html:/var/www/html
      - ./data/custom_apps:/var/www/html/custom_apps
      - ./data/config:/var/www/html/config
      - ./data/data:/var/www/html/data
    restart: always
    networks:
      - nextcloud_network
      - traefik_network
    depends_on:
      - db
    labels:
      - "traefik.enable=true"
      - "traefik.docker.network=traefik_network"
      - "traefik.frontend.rule=Host:domain"
      - "traefik.port=80"
      - "traefik.backend=domain"
      - "traefik.frontend.entryPoints=http,https"
...

I exposed the port 587 to configure the SMTP mode.
In my config.php, i get:

  'mail_smtpmode' => 'smtp',
  'mail_smtpauthtype' => 'LOGIN',
  'mail_smtphost' => 'in-v3.mailjet.com',
  'mail_smtpport' => '587',
  'mail_smtpauth' => 1,
  'mail_smtpdebug' => true,
  'mail_from_address' => 'noreply',
  'mail_domain' => 'domain',
  'mail_smtpname' => 'name',
  'mail_smtppassword' => 'password',
  'mail_smtpsecure' => 'tls',

Unfortunatly i get an error:
A problem occurred while sending the email. Please revise your settings. (Error: Connection could not be established with host in-v3.mailjet.com [Connection timed out #110])

Any idea?

Thank in advance for any help.
jB