I have a small sample size but for my SaaS which primarily sends email GMail marked as spam for a while but then gained domain trust and it hasn't been a notabl

I have a small sample size but for my SaaS which primarily sends email GMail marked as spam for a while but then gained domain trust and it hasn't been a notable issue. Outlook has my IP on a blacklist and doesn't even consider anything else. I need to send via relays to get an IP that is trusted enough for Outlook to even consider my message (which is signed with DKIM + SPF with a DMARC reject policy)