If I could snap my fingers and create one feature on ActiveRain, this might be it. I've always thought that very few people use RSS feeds and almost everyone still uses email.
Yet, we only allow someone to subscribe to your blog via an RSS feed, and not via email. But, with about 10 minutes of work, you can let someone subscribe to your blog via email.
All that you need is a Google account and the ability to listen to me ramble on for 12 minutes about how to set it up.