As mentioned earlier, Symfony2 provides a default mailer component called swiftmailer. Its default configuration looks like this:

# app/config/config.yml
# ...
# Swiftmailer Configuration
swiftmailer:
    transport: "%mailer_transport%"
    host:      "%mailer_host%"
    username:  "%mailer_user%"
    password:  "%mailer_password%"
    spool:     { type: memory }

The parameters are taken from the parameters.yml file. By default, swiftmailer sends from a locally configured SMTP host, so check your configuration and adapt it as required.

There is one configuration tweak added by default to config_dev.yml (so working only in the development mode):

#swiftmailer:
#    delivery_address: [email protected]

When uncommented and configured, it will cause swiftmailer to send any e-mail to this specific address, while in the development mode. This is a very useful option, as it allows us to test any e-mail to be sent to any user without sending the real e-mail to them.