DAP now integrates with the awesome ActiveCampaign email marketing service. See http://www.digitalaccesspass.com/blog/2014/09/part3-activecampaign/
The integration is 2-way.
There are generally 3 types of users, and this integration will work for all 3 types.
a) Subscriber joining your site via a DAP-generated free signup form, or
b) Buyer/Member buying a product or membership level, and thus getting an account in DAP, or
c) Admin adding a User manually or by importing them.
Regardless of how this user is created, anyone being added to a DAP product, will trigger that DAP Product’s settings.
And using the said DAP Product’s Plugin Notification upon User “Add” and Plugin Notification upon User “Remove” fields under the Notifications tab, you can have DAP add the user to ANY list of your choice in your ActiveCampaign account.
The integration works the other way too: When someone signs up for your list directly via an ActiveCampaign-generated signup form, you can also have ActiveCampaign add that subscriber to any free DAP product.