The authentication stuff is all standard practice so no big change IMO. However the hard spam limit with Gmail in particular will get interesting. I predict this is going to create some insane headaches for indie Saas startups. Gmail is the only inbox provider that doesn’t offer a real feedback loop (you don’t actually know if a given email address marked you as spam when sending to gmail users). The FBL in Google po…
Honestly sounds like I'm on the side of Gmail here. Think about this from the perspective of an actual spammer. You get a notification that address XYZ is marked as spam by user ABC. Well, now you just email user ABC from a different address.
The real problem is, for legitimate senders, the people who send less emails actually get higher levels of spam complaints! This is because humans are human and they forget who you are. I would argue this actually incentivizes sending more emails. This is why marketers all recommend sending garbage emails daily/weekly/monthly.
The truth is, the companies with full-time spam (marketing) departments will do just fine with these changes. It's the little guy who is going to have to navigate these complexities (likely unsuccessfully), and get shut out from yet another technology that used to be open.
On top of that, Google has started to offer perks for senders within Gmail for a $1,500 per year fee (VMC). They're basically one step away from collecting rents on all of email by way of their monopoly.