"Would you deliver the same message, in the same words, if you were within punching distance?" That pointed question—one of many in Send (Knopf), David Shipley and Will Schwalbe's witty and wily etiquette book for e-mailers—could save your skin (i.e., job, friendship, reputation, sanity), helping you avoid the emotional state that psychologist Daniel Goleman calls disinhibition and other way-too-familiar cybersins. The e-mail pratfalls anatomized by these two top-flight editors are as devastating as they are fun to read.