I recently had to just disable the Gmail spam filter using a custom rule [1] because the false positive rate was awful – 90% of the stuff in my spam folder was legitimate, including Google Calendar invites and normal GitHub communication.
Unfortunately I'm starting to get the feeling that Gmail is no longer a high priority for Google, and so it's slowly bitrotting like so many other Google projects.
[1] Matches: {(to:me) (deliveredto:myaddress@gmail.com)}
Do this: Never send it to Spam
Google Docs[0] and Calendar invites[1] themselves are often spam so i'm at least glad they don't outright whitelist domains. What is spam to some might not be spam to others.
I didn't realize how many false positives Gmail had with spam for the longest time. An astonishing amount of legit messages get wrongly flagged for my account. Given that the UI hides the spam folder, I would bet that most people have no idea how many messages they miss from this.
Unfortunately I'm starting to get the feeling that Gmail is no longer a high priority for Google, and so it's slowly bitrotting like so many other Google projects.
[1] Matches: {(to:me) (deliveredto:myaddress@gmail.com)} Do this: Never send it to Spam