Adds recipient query string details to hyperlinks.
This filter is meant for use inside e-mail templates. It replaces each occurrence of ## with the details of the subscriber that the mail is sent to, encoded as query string arguments.
Each occurrence of ## will be transformed to recipient details in the following form:
Its use case is when sending a mailing with a link in it which arrives at a webpage where the user has to enter his e-mail address and name details. Using this filter, those parameters can be conveniently be pre-filled.