It is proper Netiquette to aggregate accounts. Do use one inbox for multiple accounts.
Graymail Netiquette For Personal Email. Know settings.
It is good Netiquette to keep your address book private. Don’t send invites to people in your address book.
It is good Netiquette to accept that it is asynchronous. Don’t expect an immediate response.
It is proper Netiquette to ignore business requests from unknown contacts. Don’t do transactions with people you don’t know. We have to accept people we don’t know. We need to get to know them for real before processing a transaction.