If you have a blog and you want to use rss as a content then you can easily create an RSS campaign by following the easy steps below:
Go to campaigns
Create RSS campaign
Select a name and the list or segment as a recipients of your RSS campaign
Fill in the details of sender, subject line, and the other settings if you want
Enter your RSS FEED URL. E.g https://wordpress.com/blog/feed/ and the number of posts, then click on save and continue
open drap & drop editor and you will see the content from your blog loading
You can add logo at the top of your content and customize
Once done you can save and schedule your RSS campaign