People think, mistakenly, that etiquette means you have to suppress your differences. On the contray, etiquette is what enables you to deal with them; it gives you a set of rules.
Judith MartinEmail is very informal, a memo. But I find that not signing off or not having a salutation bothers me.
Judith MartinFor email, the old postcard rule applies. Nobody else is supposed to read your postcards, but you'd be a fool if you wrote anything private on one.
Judith MartinA small wedding is not necessarily one to which very few people are invited. It is one to which the person you are addressing is not invited.
Judith Martin