Why when you use M Outlook all my email gone from yahoomail?

would you give me solution if you use more than one PC and you want see old email after the other PC opened with Microsoft outlook you can see any more the old email with the other PC its difficult when you always traveling
Why when you use M Outlook all my email gone from yahoomail?
There is a setting called "leave read mail on server."





Myself-- I just use Yahoo everywhere, and have done so for 10 years or more. All my business mail is is on Outlook, but I see no reason to use that package to read my personal mail.