Symfony 4. Parameters for custom service

I've created a service MailService. Where is the right place for the service configuration? Is it the file services.yml? If I write

App\Service\MailService:
      someparam: somevalue

I get the error message The configuration key someparam is unsupported for definition App\Service\MailService. How to configure the service properly? How to read the params within my service?

class MailService
{
    public function __construct()
    {
    }

}

Solution

You can pass some data by constructor parameters and correct service configuration:

Service class:

class MailService
{
    private $adminEmail;

    private $adminName;

    public function __construct($adminEmail, $adminName)
    {
        $this->adminEmail = $adminEmail;
        $this->adminName = $adminName;
    }

}

Services configuration:

App\Service\MailService:
    arguments:
        $adminEmail: '[email protected]'
        $adminName: 'Admin Name'