Which of the following documents is appropriate to send using your company's email network?

Sending an announcement for a company picnic using your company's email network is appropriate for several reasons. Company emails are designed for business communication, and an announcement like this typically serves to inform or invite employees to participate in a company event, which aligns with the intended use of the email system. By utilizing the email platform, the announcement can efficiently reach all relevant employees and ensure they are informed about the event, fostering engagement and a sense of community within the workplace.

In contrast, a formal letter to a client typically requires a polished format and perhaps a hard copy for impression management and professionalism, thus making email less suitable for its delivery. An evaluation of an employee could contain sensitive information, which may not be appropriate to send via email due to privacy concerns and potential breaches of confidentiality. A dinner invitation to a colleague, while potentially acceptable, generally doesn't carry the same importance or necessity for use of the company email system in a business context compared to an official announcement like the one for the company picnic.