CRM to Campaigns SYnc

CRM to Campaigns SYnc

I am trying to link CRM to Campaigns for as part of the initial setup of my CRM Plus account. I want to make sure that CRM and Campaigns are always in sync. When I try to enter the ZSC Key I need to provide the e-mail we use for both login to CRM and Campaigns... I get this error?

An account with this email address has already been created in your org. Please contact your org administrator for access privileges.