I'm trying to configure a double opt-in link for a subscriber list. The double op-in link works perfectly only if email address is used as the subscriber key in ExactTarget. What if we have a custom subscriber key. for example 'firstname.lastname@example.org'
Double Opt-in link URL: http://cl.exct.net/sub_confirm.asp?lst=%%List_%%&eml=%%EmailAddr_%%&mid=%%MemberID%%
Is there a way we could pass subscriber key as a parameter in the double opt in link?