If you perform a task repeatedly in Microsoft Outlook, you can automate the task by using a macro. A macro is a series of commands and instructions that are grouped together as a single command to accomplish a task automatically. You can use the Microsoft Visual Basic Editor to create very flexible, powerful macros that include Visual Basic instructions. For example, you can create a macro to minimize all of the open Outlook windows.
You can assign macros to toolbar buttons or custom menus to create personalized Outlook commands. For more information about using Visual Basic, in the Visual Basic Editor, on the Help menu, click Microsoft Visual Basic Help.
Because macros can contain viruses, be careful about running them. Take the following precautions: run up-to-date antivirus software on your computer; set your macro security level to high; clear the Trust all installed add-ins and templates check box; use digital signatures; maintain a list of trusted publishers.
As a security measure to prevent the spread of viruses on your computer from macros you run, Outlook uses the High security setting by default. This means you can run only macros that have been digitally signed by the source that supplies them. Before trusting a source, you should confirm that the source is responsible and uses a virus scanner before signing their macros, because Outlook opens the macro without any warning message if the source is trusted. Unsigned macros are automatically disabled.