In order to connect a success code to a specific email address, you need to go to 'Campaigns', choose the campaign you wish to set the success codes for and go to the 'Follow-ups' section.
There in SMTP Email, you need to click on 'More settings'.
At the bottom of the page, you will be able to see all of the success codes created and a field next to them. So for each success code, you can add an email address to correspond to in the field.
You can also set up a default email address and the chats will be sent to that email address regardless of the success codes chosen.