chamilo-lms/config/packages/swiftmailer.yaml

swiftmailer:
    transport: '%env(MAILER_TRANSPORT)%'
    username: '%env(MAILER_USERNAME)%'
    password: '%env(MAILER_PASSWORD)%'
    host: '%env(MAILER_HOST)%'
    port: '%env(MAILER_PORT)%'
    spool: {type: 'memory'}