ASK HN: Any Online Customised News Notification Service?

Hi, I am looking for a service which will pull news from different rss sources provided by me and compose an email and send me at my convenient time (i.e. once in 4 hours or once in a day). Are there any such service available online? I know of some service in past but can't remember the name and couldn't find on google, which sends email or IM based on the topic filters from the list of sources which we have provided.