Client side scsnning can read things sent over Signal, Matrix, Nostr DMs or any of the two dozen other secure messsging programs.
There's no private way to send anything to anyone who has client side scanning
Discussion
That's what I'm saying
You said you shouldn't be sending anything sensitive "in this way". What way did you mean?
Well, if you're life depends on it, via e2e text to a phone if you're not sure the person and the phone/os they run. Never by email. Maybe email with pgp but even then you don't know what kind of system it will be opened on. If it's truly a matter of your personal security, the only way I would send anything electronic would be encrypted to a trusted source with a known os/device.