I've had decent deliverability to some of my Outlook addresses from my Digital Ocean droplets for about a decade. Low volume (a dozen or so a week?), only to a

I've had decent deliverability to some of my Outlook addresses from my Digital Ocean droplets for about a decade. Low volume (a dozen or so a week?), only to a few dozen addresses. I had poor deliverability until I updated the Reverse DNS to match my sending hostname. Since then, I have not had a single email get filtered.