What does it mean to preview a file in Outlook?
File preview allows you to view attachments in Outlook without opening the attachments in a separate window. You simply click the attachment icon in the Reading Pane to preview the file.
Note: You cannot preview PDF files if you're using Conversational view. For more information on Conversational view, see Learn more about Conversational view.
What files can I preview?
By default, you can preview files from most Microsoft Office/Office 365 programs including Word, PowerPoint, Excel, and Visio. You can also preview attached Outlook email items, images, and text files.
File attachments can be viewed in the Reading Pane or in the body of an email message without opening another program.
The attachment previewer feature in Outlook only works if you have the same version of Word, Excel, or PowerPoint installed as the version of Outlook being used to preview the attachment.
An attachment can appear in the Reading Pane or in the message body.
In the Reading Pane, click the attachment below the Subject line to preview the file or item.
Click Show Message or the attachment to switch between the attachment preview and the message text
Occasionally, attachments appear within the message body. The difference results from the message format.
Attachments within the message body can’t be previewed. To view these, open the attachment.
Outlook doesn't include a built-in PDF previewer. In order to preview PDF files, use the following steps.
Yes. You can enable or disable the ability to preview files in the Trust Center.
In Outlook, select File > Options > Trust Center > Trust Center Settings, and then select Attachment Handling.
Note: In Outlook 2007, select Tools > Trust Center > Attachment Handling.
To turn off all attachment previewers, click Turn off Attachment Preview.
To turn off a specific attachment previewer, click Attachment and Document Previewers, clear the check box for a previewer you want to turn off, and then click OK.
Third-party software vendors may provide their own previewers that support additional attachment file types; you can use your Web browser to search the Web to find additional information. When available, you can download and install previewers to preview additional file types in Outlook.
To help protect you from malicious code, active content embedded in attachments (including scripts, macros, and ActiveX controls) is disabled during a preview. You should preview or open attachments from trustworthy sources only.