Problems with Sync

Problems with Sync

Dear Support,

I am trying to set up a Sync between my Zoho CRM and Zoho Campaigns. Whenever I try to save the settings with the ZSC key I get a message saying:

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

I have seen on the forums that you have been able to sort this out for other users. 

Please can you help?

Many Thanks