Exemplo de como recuperar dados de configuração direto do global.php ou local.php

global.php

<?php

/**
* Global Configuration Override
*
* You can use this file for overriding configuration values from modules, etc.
* You would place values in here that are agnostic to the environment and not
* sensitive to security.
*
* @NOTE: In practice, this file will typically be INCLUDED in your source
* control, so do not include passwords or other sensitive information in this
* file.
*/
return array(
    'mail' => array(
    'name' => 'smtp.gmail.com', #SMTP do servidor de e-mail
    'host' => 'smtp.gmail.com', #No google só repetir o SMTP
    'port' => 465, #Porta do servidor de e-mail
    'connection_class' => 'login', #Diz que será feito uma autenticação para disparar os e-mail
    'connection_config' => array(
        'from' => 'teste@gmail.com', # DE!
        'username' => 'teste@gmail.com', #E-Mail de autenticação
        'password' => '12345', #Senha do e-mail para autenticar
        'ssl' => 'ssl', #Tipo do envio
        )
    ),
);

model.php

<?php
public function getServiceConfig()
    {

        return array(
            'factories' => array(
                'Contato\Mail\Transport' => function($sm) {
                    $config = $sm->get('Config');

                    $transport = new SmtpTransport;

                    $options = new SmtpOptions($config['mail']);
                    $transport->setOptions($options);

                    return $transport;
                },
                'Contato\Service\Contato' => function($sm) {
                    return new Service\Contato($sm->get('Contato\Mail\Transport'),$sm->get('View'));
                }
                
             
                
            )
        );

    }