Microsoft Outlook is an email client. Like most other email clients, you can send and receive attachments with Outlook. Outlook gives you the flexibility to customize settings for your attachments. You can configure your Outlook attachment security settings by using Group Policy Editor. Group Policy is an in-house tool that determines rules for the working environment of users accessing your computer. Note that your Outlook account has certain built-in security measures that prevent emails with malicious or harmful attachments from reaching your mailbox.
Click the "Start" menu and select "Run..." If you use Windows 7, type "run" and press "Enter" to launch the "Run..." tool.
Type without the quotes "gpedit.msc" and hit "Enter" key to launch Group Policy Editor.
Click the plus sign to expand "User Configuration" in the left.
Double-click to expand "Administrative Templates."
Double-click to expand "Microsoft Outlook 2010."
Double-click to expand "Security" and do the same for "Security Form Settings."
Click "Attachment Security." You can find attachment settings and options in the right pane.