This works great if the report requested from the autoresponder was originally published as an ezine article. List your ezine in every ezine directory that you can find - where it is appropriate. Take the time to come up with a good, benefits rich description of your ezine. Give specific subscription instructions. Since many ezine directories list ezines in alphabetical order, if you are just planning your ezine, choose a name that starts with letters near the beginning of the alphabet.
Many people scan only the listings at the beginning of the directories.
This will give you a marginal edge. Turn articles and individual issues of your ezine into webpages. Add metatags, and submit these to the search engines. Be careful not to oversubmit though. You want to avoid spam penalties.