Add Yahoo mail account to Outlook 2010-2013 without upgraded yahoo mail
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This video is a demo on how to add your yahoo E-mail account to Microsoft Outlook 2010. This requires no upgraded email just your normal one. I looked around and tried a bunch of different things until i got this to work so i hope it helps you as much as it did me.
Source: http://social.technet.microsoft.com/Forums/en-US/outlook/thread/0111c5c2-9350-464a-8950-cc0cd23a039e/
There are two different versions of this so if mine doesn't work for you go to my source link and input the other settings instead.