We definitely can help you set up an Autoresponder! To create an Autoresponder you’d first want to click the Create button in the top right hand corner of the Campaigns page in your account. You would then select Email Automation in the list of campaign options, and press create under Autoresponder Series.
Pressing this Autoresponder Series create button will then ask you to name this Autoresponder and choose the email list the series will be associated with. You can then copy and existing email from your account, or create a new email from this series.
Can an existing 'Campaign' email be turned into an auto-responder? Is there a way to either change it to become that, or create a copy that is an auto-responder?
Yes, you can copy existing emails into an autoresponder series. If you need an email from an existing autoresponder series, you will have to copy it out of the series and into your Campaigns. The copy can then be added to the new autoresponder series.