[blmayer]

If Gmail and other big providers reject email with correct DMARC, DKIM and SPF then these technologies are not doing their jobs. Why have this if you can't trust them? We need something new here, something really secure.

I am self hosting my email and had the luck that after setting up DKIM I'm no longer being sent to spam. I think it worths the effort.

[Avamander]

Because this is not just an issue of technical trust, it's also about human trust.

Good, the holy abbreviation trinity makes emails closely tied to some identity. Bad, it won't make your identity instantly trustworthy.

It is quite literally a problem without a solution, spam is not too far off from just crimes like littering, it needs legal methods against.