Back in April 2011, we had posted an article about the new features in Yahoo Mail Beta. Though Yahoo Mail has improved a lot, it has also added a little bit of annoyance by making the preview pane hard to find.
On the said post, several users have been discussing how to show the preview pane in Yahoo Mail beta, but it looks like most of the information available might not be helpful.
I recently wanted to enable this feature in my own account and found going around circles with no preview pane in sight. Turns out that the Options -> Mail Options -> General -> Show all messages in a scrolling list (with Preview Pane option) does not change anything.
However, I found another trick which can be used to display the preview pane in Yahoo Mail Beta. The trick is really silly but not many people will be aware of it.
In order to enable the preview pane in Yahoo Mail, go to your Inbox and click on the "Switch view" button next to the "Actions" button. From the available option select "In Scrolling List (With Preview)" option. Yahoo Mail will say that it needs to refresh the page to change the settings. Click on Ok and you should now see the preview pane below the email messages.
I have tested this change in multiple browsers including Google Chrome, Firefox and Internet Explorer 9. Unfortunately, the new version of Yahoo Mail Beta does not support Opera. If you aren’t able to see the preview button in Yahoo Mail, you might want to try going to options and changing the settings.
If the above solution does not work for you, you can try logging in to Yahoo Mail using another browser and making the changes. The change is sticky, so it will then reflect across all browsers.