Effective email communications with customers requires considering factors like the purpose of the email, maintaining civility, and properly structuring messages. Emails should be used for sharing offers, documents, and updates while instant messages are better for quick questions and conversations to save. It is important to identify the goal of each email as to get an answer, inform someone, or have them take action. Issues can arise if emails aren't read, aren't replied to, requests aren't fulfilled, or work is done too late. Messages should use tags or brackets in subjects, have small signatures, and share long instructions as attachments to be concise and respectful.