Outlook Express won't work if you try to use your free yahoo.com email through it. The only way you can use Outlook is to sign up for Yahoo Plus and pay for it. There are few regulations regarding the internet, so there could be no laws prohibiting them from doing this. There is an organization based in Virginia and Geneva, Switzerland with branches throughout the world called the Internet Society (ISOC) which was incorporated as a non-profit organization to influence legislation and laws regarding the internet.
The ISOC claims its mission is: to assure the open development, evolution and use of the Internet for the benefit of all people throughout the world. Its members consist of individuals, corporations, organizations, governments, and universities. ISOC claims membership is currently free- and membership is open to anyone, but when I got on their site I saw they offer two individual membership levels. The sustaining membefship costs $75 annually. Global membership costs $100,000. The list of Global members is long and includes major internet related corporations like Microsoft.
The ISOC was officially formed in 1992 to provide a corporate structure to support the ad-hoc bodies active in the growth of the Internet. If you can or can't do something on the internet, or access sites, it is most llikely because the major corporations who have Global membership like Microsoft have decided, whether for security reasons or other reasons, that you can't use the feature or program unless you pay for it.
None of us want to see laws prohibiting access to the internet. Unless you can convince your legislators to introduce a bill prohibiting any organization or entity from controlling access to the internet, the most you can do is boycott those businesses who try to force you to pay additional fees to use a program for which you've already paid, such as Outlook Express. In addition, Microsoft is notorious for not providing information to fix error messages. A frequent error message you will receive when using Microsoft is Error #404 which you can research on Wikipedia. Error #404 is frequently used when a corporation, organizaiton or individual doesn't want you to access or see an internet site.