Gmail is blocking emails with links to Tutanota
twitter.com
twitter.com
I assume they hard coded an overzealous rule to catch people/scammers obscuring URLs with long IPs, but instead it even caught legitimate domains (though only developers tend to use such names).
No matter how many times I tweaked and ran the algorithm, it would always arrive at 73% accuracy-- because one of my inboxes was almost exclusively spam-- and every time the rule it would discover was to discard an e-mail when it had discovered juuusssttt enough of the domain name of the offending mailbox from the header.
So, if the email address was someting@news.ycombinator.com it would discover any email containing the phrase "news.y" was more often then not, spam. This would immediately lead to a huge increase in accuracy but the algo would be stuck a at a local maximum since it hadn't really learned anything useful.
It seems that recently the IP block that my mail server's IP address is in got listed in a Spamhaus database. I checked neighboring IPs, and they're all listed in Spamhaus. Spamhaus has a very easy easy procedure for getting off the list, and I was able to get my IP address removed from their list, and https://www.mail-tester.com/ reported 10/10 score again (meaning SPF, DKIM, DMARC are all kosher).
As others have mentioned in the comments of this answer [0], removing from the Spamhaus database still doesn't fix the issue. So this indicates that Gmail doesn't update their Spamhaus database too frequently?? Or, once you're on their block list, it's very hard to get off of it.
"Why Tutanota is the most secure email service."
Although I see their CTO is based in the US so it is certainly possible.
Their clients are open source so you should be able to build them yourself. https://github.com/tutao/tutanota/blob/master/doc/BUILDING.m...
How would that court requirement work ?
Yeah that's the technical detail no judge has any interest in solving ;) ....like upload filters..