Is it there a facility to automatically add the sender address in th YAHOO! MAIL System?

you need for them to give you there correct email to add them i think ,

Not sure what you are asking here. If you have put all your email addresses into the yahoo address book in your yahoo email, then all you need to do is click compose at the top left, click the tiny blue letters saying insert addresses just over the to line and the address book pops up, just tick the address you want and click insert checked contacts. The address will then automatically go into the to space.

When you receive an email, at the side of the senders address it will say add this contact to your address book, just click that to put a new address in that you received a mail from.

Hope that helps.

I was going to say the same as blue dolphin at the top, but I'll just leave it in her words..lol