Unread email tile preview is only for Hotmail?

[WPer]

I really like the feature of unread email preview on tiles. But it seems that the feature is only for Hotmail account? I have an email account that I don't want to link with my Hotmail account. So it is created with an Outlook icon in the app list. When I pin the account onto the start screen, it only shows number of new emails but not the preview. Is it by design or there are some settings that I am missing?

Thanks.

Update: I found that only the largest tile has the preview but I am always using the middle size tile... Please ignore my stupid post.