Online Attachment Viewer
If You can add Online Attachment Viewer Without need to download files Locally and Open it on local Machine Such as PDF, Excel, Word, etc...
The latest version of WorldClient includes the ability to view PDF files online without the need to download the files.
I'm a fan of http://www.backupthat.com for their attachment viewer. They let me use all the metadata I would get in searching an email, but I don't have to search through all my email threads to find them. They are neatly pulled out to the side for me. And they work in any email client.