OE deletes mail from Yahoo Inbox

Once OE collects mail from Yahoo the mail disappears from the Yahoo Inbox. Furthermore, if I send from OE the sent mail doesn't appear in the Yahoo Sent box.

Is there any way to ensure that mail to and from OE remains in Yahoo?
I can't see anything in OE's options which do this.

1.


On the Outlook Express Tools menu, click Accounts.

2.


Click the Mail tab, and then double-click your e-mail account.

3.


Click the Advanced tab.

4.


Check the box labeled "Leave a copy of messages on server." Doing this activates two clean-up options:
•

If desired, check the box to "Remove from server after 5 days." You may change this to any number between 1 and 100.
•

If desired, check the box to "Remove from server when deleted from ‘Deleted Items.'"

http://www.microsoft.com/windows/IE/...ailserver.mspx

Thank you again.