What is the general set of expectations for how people should communicate when sending electronic mail called?

The term that best describes the set of expectations for how people should communicate when sending electronic mail is Email Etiquette. This concept encompasses the respectful and appropriate behaviors that individuals should adopt while composing and sending emails. Email etiquette includes aspects such as using a clear subject line, addressing recipients appropriately, maintaining a professional tone, being concise, and using correct grammar and spelling. Following these guidelines helps ensure that communication is effective, respectful, and fosters a positive relationship between the sender and recipient.

While other terms like Email Standards, Email Protocol, and Email Practices may have relevance in specific contexts—such as discussing technical specifications or common behaviors—they do not encompass the full range of social and communication norms that define how to appropriately interact via email. Therefore, Email Etiquette is the most accurate answer in this scenario.