Aweber Single Optin Doesn't work with API Integration

Unfortunately Aweber does not allow subscribers to be set as single optin when using the API integration method - your subscribers will always be sent the double-optin message.
 
This is not something that we can change for Aweber - it is set within their API system
 
The workaround is to use the custom form integration method for any opt-in forms that you must have as single optin - you can find out more about how to do this here: