Google is like this - their anti spam tools are only available if you *are* sending UCE. The small private domains sending a few hundred to a few thousand emails to gmail addresses annually cannot get access to them.
I have all the things set right: DKIM, DMARC, SPF, IP is in a "good neighbourhood", all the blackhole lists show my IP as clear, yet sending "hey, nice meeting you today, here's my email, looking forward to speaking with you again" type emails to a new gmail address almost always end up in their junk. And there's nobody to contact at Google about it -- it's a completely automated system.
Microsoft has their junk mail reporting whatever and registering with them (not an easy thing to find until you know what it is) solved all my outlook.com issues.