I use talend, and they have a marketo component which marketo acknowledges
http://www.marketo.com/customers/talend/
This is not a talend question:
I am able to use sync to update user info - which works well; however, I receive an error if the user doesnt exist. I use email as the target key - as its not possible to know the marketo id.
Are there marketo configurations that need to be updated to allow new users through API?