I am so sorry for late .
The method that I have found doesn't work !
But I have just finished searching for another solution and I have tried it
1-Use Gmail account and add it to your yahoo group account
instructions here
Code:
http://jrocas.com.ph/archives/how-to-use-gmail-with-yahoo-groups/
2-connect Gmail to outlook
instructions here
Code:
http://mail.google.com/support/bin/answer.py?answer=75291
This help article for outlook 03 which i use
Note: you must have Outlook '03, '07 or '10 !
type what the version you use in the gmail help if you are not use 03 version
3-As my searches results there is no way for adding all senders emails addresses to
the contact list in any free email services !
But you can use this tool "Clearcontext"
Code:
http://www.clearcontext.com/index2.html
Download it and install (Note: you must have Outlook '03, '07 or '10 !)
It will be as a plugin into your outlook

After you have successfully installed it , you will use the feature "contact exporter"
How to use it From here
Code:
http://www.clearcontext.com/user_guide/contact_exporter.html
You will export as .csv file which is you can import in yahoo or gmail or other email services
I hope this will help you
I am Sorry again for late and sorry for my bad English
Good luck , blackhaters