I can understand the difficulty in judging new domains, but having established, high value, high volume domains getting their email flagged as spam is ridiculous.
It could also be anti-competitive behaviour. They want the system to be a complex, opaque, black box because then it's more important for other providers to trust their IP ranges because they're a known-good participant. If you're a small sender that wants decent deliverability your options are Google, MS, etc..
"Your domain is about to expire, enter your Google username and password to renew it!"
If it was me, I'd pattern those emails to be exactly like the real ones. So then the real ones might get flagged by the spam filters too. You'd think they'd check who's sending them though (origin server)...