ifttt - IFTTT puts the internet to work for you. Create simple connections between the products you use every day.
Blogtrottr - Track RSS feeds and send updates to your email inbox.
Feed2Mail - Feed2Mail notifies you when your favorite feeds and websites are updated.
Mailbrew - Automated email digests from Twitter, Reddit, YouTube & more
Huginn - Build agents that monitor and act on your behalf. Your agents are standing by!
Feedbutler - Subscribe to your RSS feeds directly via email!