If you use Community Builder, you can use our Plugin for Community Builder to automatically add a user to your Mailing lists when he registers on your website.
This article contains some queries that you can execute with PhpMyAdmin.
This section is for information only to experimented users and it's considered as a hack of Acajoom but it can also allow you to do whatever you want with Acajoom.
Before executing any query, please make sure you understand what the query will do and export your database before doing anything so you will be able to re-import it again if the result is not what you expected.
This article will explain you how Acajoom sends your Newsletters so you will be able to understand the whole process and optimise it to avoid any error.