Spam messages in Signal

enable "block unknown" just below the "blocked users" in settings

I've never once had this issue while I get normal SMS spam. My grandpa and wife get them though. Still trying to figure out why. I'm about to make the switch to Molly as I read you can allow messages only from an approved list of senders or something along those lines. Molly is a fork of Signal FYI, and you'll need their fdroid repo to download or get it from github

You can report the message so that future messages from the spammer won’t send. Unfortunately no direct way to mark the message as junk automatically like email, but Signal does have Message Requests which may help? https://support.signal.org/hc/en-us/articles/360007459591-Signal-Profiles-and-Message-Requests

They need to offer a move away from numerical user ids. What is that called, where you can guess or arbitrarily determine something algorithmically or formulaically or like throwing a dart randomly and hitting a real identity to exploit?

Also the same deal when people use numeric pin codes. If the replay mechanism is screwed, its literlaly only a matter of time

One of the secret sender options is to disallow messaging from anyone (I think it's on mobile), though I am not sure what portion of spam this blocks

Did they get your number to send spam?

I'm not aware of any functionality which allows to block messages from unknown users. I think blocking them might be your only option right now.

Easier said than done (and already too late for you), I know, but: in general, be careful where you leave your number...