Email config conflict

I have the pro plugin and trying to configure the email setup. However i get the error

New User Email Configuration Conflict warning: You have another theme or plugin installed that is preventing s2Member from controlling this aspect of your installation

I have gone through all my plugins which are not many and I can’t get rid of the error? Any ideas what to look for now?

It look like the system uses S2Member paypal emails when I’m using Stripe Pro to register users???