Log into your E-goi account, go to the "Lists" menu, head to the list you want to feed sign-ups to and hit "Options". On the options page, just go to the "Webhooks" section.
Then simply select the service you want to integrate with, click "Generate URL" and follow the instructions provided. Done! :)
When you're finished, any sign-ups from the external service you've chosen will be fed to E-goi and be sent any autoresponders you have previously setup in E-goi!
Which services and apps does E-goi already integrate with via webhooks?