What does zz mean on Outlook?

Could you please clarify what you mean by "zz" on Outlook? Are you referring to a specific feature, setting, or abbreviation that appears in the Microsoft Outlook software? If so, could you provide more context or an example of where you've seen "zz" used in Outlook? Without more information, it's difficult to give an accurate explanation as "zz" could have various meanings depending on the context. Alternatively, if you're looking for general information about using Outlook, I'd be happy to assist with that.