Which of these is not generally a good practice for telephone use?

Using voicemail systems and answering machines that do not require a password or PIN for access is not generally considered a good practice because it compromises the security of the stored messages. When voicemail systems lack password protection, anyone who has access to your phone can easily listen to sensitive information and personal messages. This lack of security can lead to unauthorized access, increasing the risk of breaches of privacy and confidentiality.

In contrast, the other practices, such as utilizing password-protected systems, ensuring privacy during conversations, and keeping callers informed about wait times, enhance the professionalism and confidentiality of telephone communications. These practices help maintain trust and respect in communication while safeguarding sensitive information.