I subscribe to about 100 RSS feeds and one email newsletter: Money Stuff. I wanted a way to receive Money Stuff in my RSS reader instead of in my inbox. Unfortunately, Bloomberg doesn't seem to offer an RSS feed for Money Stuff anymore.
I found a website called Kill the Newsletter that converts email newsletters into RSS feeds. For each newsletter you want to subscribe to, Kill the Newsletter gives you a brand-new, unique email address and Atom feed URL. You subscribe to the newsletter using the email address and add the feed to your RSS reader. When Kill the Newsletter receives a newsletter email, it converts the email into a post and adds it to the feed, so that it shows up in your reader.
One disadvantage is that my RSS reader doesn't refetch feeds very often. There's some delay between the newsletter being sent out and me receiving it, whereas I get a notification about the email version as soon as it lands in my inbox. My RSS reader does give me the ability to manually refresh a certain feed, which mostly addresses this issue.
Overall, Kill the Newsletter has worked well for me. I plan to use it for more newsletters in the future.