How large is our “blocked senders” list allowed?

Everyday I have to block anywhere from the high teens to high 20's from my email. Spam is something in hotmail and live.com I don't understand. It engorges the accounts where my gmail account has very little problem with it. I have the account set to "exclusive" but this doesn't stop the spam. I might block a dear friend until I find they want access but the spam rolls in everyday with such suggestive and lewd titles I won't even mention. I thought this was only a problem on my old hotmail account dating to 1996. But when I created a new account with live.com just a few weeks ago the spam starting rolling in and now it's par with the old hotmail account. But to my original question, how large is that blocked senders account allowed to be. I can see where in a year or so I'll have 1000's there and many more each day?