Summary / TL:DR: This article will show you how to use unsubscribe pages in SignupApp2
In order for the unsubscribe link to work from an email that was sent by Blueshift in existing lists, these hidden HTML fields must exists within the source of the unsubscribe page, otherwise you will receive an error
<input type="hidden" name="emailId" value="[%= emailId %]"> <!-- DO NOT REMOVE THIS INPUT -->
<input type="hidden" name="campaignId" value="[%= campaignId %]"> <!-- DO NOT REMOVE THIS INPUT -->
<input type="hidden" name="experimentId" value="[%= experimentId %]"> <!-- DO NOT REMOVE THIS INPUT -->
<input type="hidden" name="bsft_ek" value="[%= bsft_ek %]"> <!-- DO NOT REMOVE THIS INPUT -->
The form HTML should include all of these fields:
Keep in mind this is only for existing lists. Newly created lists in SUA2 will automatically have these fields injected into the HTML source.
Wrap up
You should now know how to use unsubscribe pages in SignupApp2