Why i can send e-mail to member of the answers?

I checked your profile, and no, you have not set up email. You have your email address set up, I'm sure.

But, Yahoo! Answers has a email communications system that is separate from your email. To enable your email on Yahoo! Answers:

Go to your Privacy and Communications and check these box(es), depending on which ones you want

http://answers.yahoo.com/my-activity/edit/settings

The Answers Community Can Contact me:

[✔] Via Email (Your address will remain private) ← you're looking for this one.

[✔] Via Yahoo! Messenger.

Click Submit.

Now, try messaging the person again and you'll be taken to a message screen instead of the "you need to enable..." screen.

Place your cursor over the My Activity tab at the top of the page above the green line.

- a menu will appear

Select "Edit My Preferences"

On the next page, select "Privacy & Communitcations"

Under "The Answers Community can contact me"

- check the box next to "Via Email"

Enable your email first.Click your avatar, click edit my preferences, click privacy and communications. scroll down under The Answers Community can contact me:

check via email and or Yahoo messenger click submit.

Then. you could click on their avatar, if they accept ims or emails click on the appropriate one and follow the prompts.