Send Mails From Gmail As Yahoo Mail ???

This Title Seems Strange To You Here's The Explain What We Mean By This Title:
You Have Several Email Accounts in Yahoo and Gmail and You Want to Use Gmail Only to Send Mails But You Want You Mail Seems to Be Send From Your Yahoo Account Here's How You Can Do That:

1- Open Your Gmail Account and Choose Setting

2- Choose Accounts and Import Tab and Choose Send Mail As

3- Add Your Name and Yahoo Account and Press Next

4- Choose accept The Default Setting and Press Next

5- Now Gmail Send You (to Yahoo Account) Mail With Verification Code and Link

6- Copy The Verification Code You Received in Yahoo  and Paste it in Gmail As Show Down and Press Next

7- and Go Back to You Yahoo Mail and Click on The Link Gmail Send to You to Confirm You Accept That

8- Now When you Compose an Email in Gmail Will Give You Option to Send The Mail As Gmail or Yahoo Account 

Now You Can Send Mails From Gmail As Yahoo.

Have Fun !!!!!