When is it appropriate to send an instant message $($IM$)$ or text message versus a conventional e$-$mail or fax? Of the following which is best for an email over an IM$?$

Question $5$ options:

Informal use among peers at similar levels within an organization

You need to communicate but time is not the most important consideration

You're running about $10$ minutes late to lunch.

Email is best for all of the above.