Is there any among the popular instant messenger platforms that is:
1. reliable, that is I can trust it to deliver messages (I can’t believe I have to start with this one),
2. has a _permanent_ log of all messages, photos, and files sent, i. e. it does not allow others to delete either their or my messages, and does not allow to send messages that automatically disappear after some time, and allows me to transfer these logs to my desktop in a non-proprietary format,
3. and does not share things with others I don’t expect it to share, like my location, if I made a screenshot, etc. (online status and read receipts I have basically given up on).
Thanks an advance.
A private IRC server?