Is there a service available which pings a list of website after every few minutes, let say after every 45 minutes and if the website is down i.e. ping failed then send a notification through email.
If this kind of service is free then great if not then i can also look at the non-free ones.
There are a lot of services who do this. I don't know if any do it for free.
In this thread in the Hosting section a lot of services you ask for are discussed.
Hope that helps