Returns an external key that is used to identify the current recipient according to the system that delivered the recipient. It will often be the User.ID fra User Management because the Dynamicweb Recipient Provider is the most used provider.
The value is generated automatically.
The EmailMarketing/EmailMessaging tags are not rendered for a normal page that is not used with Email Marketing. The tags are only rendered when the page is used in the context of an email from Email Marketing.
You can e.g. use the tags in a design page template and assign it to the page that you want to use for the E-mail marketing newsletter.