Yahoo is appending unwanted news headlines to the end of received emails

[Carya]

When I receive mail through my Yahoo account in Zimbra desktop, random news stories are added at the bottom. This does not occur when I read the mail over the web on yahoo.com. They are not advertisements, but news. They show up inside a gray box. Here is an example:

TODAY(Beta)
Prank on woman ends just in time
We get a little worried for a gullible passer-by when she's rattled by an "Avatar" star's lie.

Powered by Yahoo! • Privacy Policy

I cannot figure out any way to turn these off, either from within Zimbra desktop of within Yahoo preferences, including the link to their "privacy policy" which they cite. Does anyone have any knowledge about this unwanted "feature" and how to get rid of it?

Thanks.