It is considered best practice to send notifications and emails in the recipient's preferred locale. Laravel supports this out of the box through the HasLocalePreference contract, which enables you to easily define a user's locale preference:

use Illuminate\Contracts\Translation\HasLocalePreference;

class User extends Model implements HasLocalePreference
{
    /**
     * Get the user's preferred locale.
     */
    public function preferredLocale(): string
    {
        return $this->locale;
    }
}

Once you implement the HasLocalePreference contract, Laravel will automatically use the preferred locale returned by the preferredLocale method when sending notifications and emails.