Now, steelman argument is that DMARC is used together with SMTP, so it should be somewhat compatible to work in practice. But in this case there isn't fundamental conflict breaking SMTP.
I don't agree about that ZFS issue. Using whole disk isn't inheritantly wrong. When you have data pool separated from boot disks, using whole disks is better. No need to create partition table, when replacing disk. No worring over block alignment.
MID-s are used by MUA-s for referring earlier messages, tracking answers and so on. So any software expecting dialog (messages coming back) needs to deal with MID-s correctly. Missing MID-s show that said communication is one direction, because broken dialog has not been problem.
My take, as a postmaster for hosting company, who don't have any sympathy to gmail (that should be visible from my comments history):
Message-ID is absolutely MUST in production e-mails. You can send your test stuff without it, but real messages always have it. Not having Message-ID's causes lot of fun things. All somewhat competent software is capable to add Message-ID's, so lack of it is good indication of poorly made custom (usually spamming) solution.
Rspamd and spamassassin have missing MID check in their default rules, I am sure that most antispam software is same.
Testing with different ISP-s involved ISP provided resolvers and directly using archive.today nameservers. I know that archive.today has previously blocked common public resolvers, like 1.1.1.1. That case they replied with 127.0.0.4 or other loopback IP addresses.
Thats true for several other speeds too. 100GE first generation was 10x10GbE, second generation was 4x25GbE. 200GE first version was 25GbE based and so on.
If you add additional piece to chain, chain becomes weaker, not stronger
> get AI-DoSed
Thats not that common. There are specific industries prone to DDoS, like gaming, but your average site don't get DDoS-ed. Then again CF free service really don't protect your site from DDoS. I have seen several times CF becoming source of DoS (not caching or denying malicious requests) and if back-end is on shared infra, CF goes to firewall.
That name NDP looks little bit confusing. For example, wikipedia article https://en.wikipedia.org/wiki/Neighbor_Discovery_Protocol shows NDP as Neighbor Discovery Protocol, even when RFC-s themselves don't use that abbreviation.
That article had weird statement about PCI-X: "It did not see wide use with PCs, likely because Intel chose not to give the technology its blessing, but was briefly utilized by the Power Macintosh G5 line of computers."
I don't know, what they meant with blessing, but Intel server motherboards had PCI-X slots and this was common bus for servers/workstations. Mostly used by SCSI and RAID controllers, high-end network adapters.
Putting on my "postmaster at shared hosting company" hat:
Used to be. Gmail is done lot of work to be worse than Outlook. At least MS idiosyncraties are somewhat known and stable. I would say that most customer complaints are related to gmail.
What OP means by cloud provider? Cloud is overused term.
That said, we have Hezner, OVH and Scaleway.
You can ask other way: why US don't have cheap well known bare metal provider.
Arkady and Boris Strugatsky. If you start with their earliest work, like "The Land of Crimson Clouds", you can get vibe, how communist Sci-Fi looked. If you read later stuff, like "Tale of the Troika", then you get story humorously criticizing soviet bureaucracy. Then there is pretty serious stuff, like "The Doomed City" or "Ugly Swans". You probably know "Roadside Picnic" - this interpretations in films and gaming are known as "Stalker".
In the last few years some Usenet providers are closed their doors. Aioe.org was pretty popular and known, disappeared this year. One of few ISP-s still offering Usenet access for clients, Finnish Elisa, closed their usenet server 2021.
Russian neva.ru was sadly closed (probably forced by goverment) 2021 (I group it with free servers, because it had read-only access open for everyone and some point allowed posting). Albasani.net disappeared 2020.
Some free servers are still around, but don't offer public accounts.
Few places give account, if you ask.
Eternal September is strongest-biggest still running and free service. Mixmin allows anonymous posting, but sometimes restricts it to fight with abuse.
Google still relays groups to Usenet, though they have their own thing going and some servers are blocking posts from google.
Now, steelman argument is that DMARC is used together with SMTP, so it should be somewhat compatible to work in practice. But in this case there isn't fundamental conflict breaking SMTP.