http://nguipxnkrp3qrzrlduhsatpcpwehnblzmlkc5ifiumxq4z5jlh4lwvid.onion/os_archive/os_OPSEC_357.html
Get a tape deck and a cassette for phone messages with a physical control (play stop and rewind buttons) (mechanical requires physical access). Don't use a "digital mail box" at the phone company to store your messages. Don't ever respond to telephone surveys, (Phishing attempts) just tell them no thank you I'm not interested , and hang up, and do this politely (say thank you, have a great day and hang up).