Downsize a picture attachment in Outlook 2010

After you have attached an image to a message in Outlook 2010, click the File tab. The backstage view of the message window will open in the Info category. Choose the option at the top to "Resize large images when I send this message." Images will be a reduced to a maximum of 1024x768 pixels, which must be done on a per-message basis. Click the File tab again to return to the message window.