Because usually it's the browser that subscribes to the RSS feed, not an email client.
Why? Because, when you subscribe to an RSS feed, the RSS feed is none the wiser. When it updates, it doesn't have a list of people to tell; Rather, when something (e.g. your browser) checks it and it has been updated, it picks up on that and decides to alert you. The fact that you have subscribed tells your browser to check it regularly.
There may be online services that alert you by email when a feed updates, but your email client won't do that automatically.
If you want to be taken seriously, you really need to work on your grammar and stop using shortened words e.g. 'y' for 'why'. You'd be surprised how much using full words and correct grammar affects what people think about you.