"As its name suggests, Aaron Swartz's GPL-licensed rss2email
utility converts RSS subscriptions into email messages and sends
them to whatever address you specify. Despite the name, it handles
Atom feeds as well, so you should be able to use it with just about
any feed you like.
"Why would you want to receive feed updates in your inbox rather
than checking them in a feed reader? Isn't the whole point of feed
subscriptions to browse them at your leisure...?"