I hate how there is only 1 type of message. I often want to send something that isn't urgent enough to make their device bleep. Sending to spam could also be a useful marketing tool.
The email filtering topic had me think it would be useful to offer some options if you received mail from multiple potentially bad actors since the last time you logged in. Beyond 4-8 I wouldn't want it in my inbox.
Perhaps some cryptographic contact of contact is also possible.
If something is urgent they should call me. Messages depend on the person. But emails are well within the category of reading whenever I have time, every other day or so. If people's devices beep every time anyone sends them an email, that's their choice.
Which is not to say that a priority indication can't be helpful. Telegram has "send without sound" as an option if you long press the message button, which I use at night with my mom because I know she usually leaves sound on 24/7 (apparently other, "normal" people don't message after midnight!).
Email has this system too but the other way around (priority flag) and I've received about a dozen high-priority emails, mostly while interning at a bigcorp. They could literally all have been deleted unseen. People set the flag when they think you'll otherwise not read it, it's that level of useless.
There's also a low-priority flag that I've seen used maybe once ever. You could start using that if you're worried someone has standard emails set to audio notifications.
The email filtering topic had me think it would be useful to offer some options if you received mail from multiple potentially bad actors since the last time you logged in. Beyond 4-8 I wouldn't want it in my inbox.
Perhaps some cryptographic contact of contact is also possible.