Answer and explanation:
In e-mail messaging, the phrase "low expectation of privacy" refers to the sender must compose the message as if it would be received not only by one person but to a wide audience who might be involved in the subject why the e-mail is being written for.
For business professionals, it represents keeping a formal registry at all moments even if the person to whom the message is being sent has a close relationship. The message could be sent to somebody else or could be read accidentally by another person.