The extension is made up of several parts:
the component (manage your lists, import users, create drafts with contents from your site, send campaigns, autoresponders, view reports, etc)
the registration plugin (give users the choice to subscribe for your newsletter when they sign up for your site. Also allows users to change their preferences in their site profile)
the subscription module (place a subscribe form in any module position on your site)
control panel module (displays campaign reports on the control panel so you can easily track your campaigns)
3rd Party Integrations: joomlamailer's rich feature list can be increased by having compatible extensions installed. K2 for example, a popular content component. In this case you can also add items from K2 to your newsletter.
other compatible extensions: - Jomsocial - Community Builder - Ambra Subscriptions - Access Expiration Control (AEC) - Virtuemart