How are you verifying this? I encourage you to try sending to a gmail address you have never sent to before, I virtually guarantee you are going to end up spamboxed.
I know lots of people that run low volume personal type servers, many have claimed that gmail doesn't spambox them, but they were always testing on a (handful of) personal account(s), when I got them to check with an account they had never mailed before, they were spam boxed literally 100% of the time.
Properly setup, and strict FCrDNS, DMARC, DKIM, SPF, TLS and a clean IP and an old domain that have both never sent spam are absolutely not enough to avoid gmail's spambox.
I have verified it by helping people sign up for the small service I run and seeing the e-mails pop in their primary inbox. I guess I might be lucky then shrug.
I know lots of people that run low volume personal type servers, many have claimed that gmail doesn't spambox them, but they were always testing on a (handful of) personal account(s), when I got them to check with an account they had never mailed before, they were spam boxed literally 100% of the time.
Properly setup, and strict FCrDNS, DMARC, DKIM, SPF, TLS and a clean IP and an old domain that have both never sent spam are absolutely not enough to avoid gmail's spambox.