Help for Windows Live Mail can be found here - http://help.live.com
Discussion for Windows Live Mail can be found here:
http://www.microsoft.com/communities/newsgroups/en-us/default.aspx?dg=microsoft.public.windows.live.mail.desktop&cat=en_US_0405EAE1-3A5E-559F-59E6-B48513D5B57E&lang=en&cr=US
As for the OneCare issues, I don't what what you mean by never accepting the serial numbers. OneCare is either activated or not. If it is activated, you have a subscription. If it is in trial mode, it will expire and you will not be able to use your key to activate a new subscription since OneCare is at end of life. You may be entitled to a refund if you did not actually activate.
See this post for End of Life information for Windows Live OneCare - http://social.microsoft.com/Forums/en-US/onecaregeneral/thread/81996436-edad-41ba-bdfc-02fc094e2ca9
If the OneCare firewall is off when your boot, meaning OneCare is in red status, and you need to turn in on manually, try the Firewall repair tool -
http://social.microsoft.com/forums/en-US/onecarefirewall/thread/e67b1989-afd5-47e5-a393-3a551c7c7e60/
You may want to contact support if that doesn't work and you have an active subscription.
How to reach support (FAQ) - http://social.microsoft.com/Forums/en-US/onecareinstallandactivate/thread/30400b52-7f26-4ba0-bc18-17e305329d90
-steve
~ Microsoft MVP Windows Live ~ Windows Live OneCare| Live Mesh|MS Security Essentials Forums Moderator ~