A command-line switch is the addition of a forward slash followed by the command name and any parameters. In Outlook 2013 and Outlook 2016, you can change certain aspects of how the program starts by adding subcommands called switches to the outlook.exe command.
A switch appears as a space after the main command, followed by a forward slash and the name of the switch, which provide additional information about how to execute the command.
For example, the following command instructs Outlook 2013 and Outlook 2016 to start with the Reading Pane turned off.
First, verify the location of the outlook.exe file on your computer. If you accepted the default folder locations when you installed Outlook 2013 and Outlook 2016, the outlook.exe file is located at the following:
For Outlook 2013: c:\program files\microsoft office\office15. If you installed Outlook 2013 32-bit on Windows 64-bit, look here: c:\program files (x86)\microsoft office\office15\outlook.exe
For Outlook 2016: c:\program files\microsoft office\office16.
Tip: If you can’t find the outlook.exe file at the locations listed above, search for the file and note the full path.
Click the Start button, point to All Programs, click Accessories, and then click Run.
In the Run box, type a quotation mark, enter the full path for the outlook.exe file, and then type another quotation mark. Alternatively, click Browse to locate and select the file. In this case, the quotation marks are supplied automatically.
After the closing quotation mark, type a space, and then type the switch. For example, you might type:
"c:\program files\microsoft office\office15\outlook.exe" /nopreview
The next time you start Outlook, the program opens as usual. To make your customized startup available for repeated uses, see the next section.
Switches are not case-sensitive. For example, /NOPREVIEW functions the same as /nopreview.
Remember to include one blank space before the switch and one before each parameter.