Who is this article for?

Administrators who want to learn to preview emails and documents.

No elevated permissions are required.

This article outlines how preview functionality works for emails and documents stored in SharePoint.

1. Preview emails and documents

Previews of email and documents stored in SharePoint are available within integrated applications.

If a web-based preview server is available, supported file types such as office documents and PDF files will be rendered using server-side preview technology.

If the preview server is not available or the file type is not supported (e.g. email message files), the file will display as a local preview.

1.1. Thresholds for local preview

A local preview option is available when server-side preview is not accessible. An administrator, or an end user if permitted, can adjust settings to manage local preview behavior.

Any file size greater than the warning size will require the user to explicitly request the preview. Files exceeding the maximum size will not be available for preview. These items can still be opened from SharePoint by double-clicking on them in the view.

1.2. File types

The file types setting allows control over which file formats can be viewed using local preview. These settings work in combination with threshold settings.

1.3. Preview cache

The preview cache defines the maximum amount of disk space allocated for storing cached files used in local preview.