PLEASE NOTE: this article applies to our older (V2) templates only. It does not apply to templates built with our Standard or Drag & Drop Builders.
When opt-ins are being sent via API, Constant Contact does not add them if they are present on one of your other lists already.
Constant Contact's API (the system we use to integrate with Leadpages) is designed to check if an email address that we send is on any of your lists already. If that is the case, the email is being treated as already subscribed and is not being added to your (new) list.
This a policy by Constant Contact and our previous form builder follows it. In other words:
If you want to have the same subscriber on multiple lists, you will have to use a multiple fields (V3) template.
Please let us know if you have additional questions.
You can always file a support ticket if you have additional questions by clicking the Support button in your dashboard shown here or clicking here to file a support ticket.