> After researching the topic it turned out that the internet now runs on an IP reputation system. Major email services like gmail assume that anything sent from unknown IPs is malicious.
You have to buy/rent a dedicated IP address (that you'll be able to keep long term), and it warm it up by gradually increasing mail volume over a few months to weeks. But once you have, deliverability shoudl be fine.
I think the bigger issue is needing to keep on top of mainenance of the server.
Like the parent have ran Email servers for many years now. If you get a bad IP, as long as you get the DKIM records right, over time it will 'warm' up the IP. And the more you use the email on that IP and NOT spam people. The IP will warm up. Make sure you actually own that IP!!! It will become valuable.
Key point - own the IP. We own our IPs and we also buy elastic IPs from AWS. The entire AWS subnet (it seems their entire address space) is universally garbage and unwarmable. Our own IPs have hummed along for years with zero issues.
You have to buy/rent a dedicated IP address (that you'll be able to keep long term), and it warm it up by gradually increasing mail volume over a few months to weeks. But once you have, deliverability shoudl be fine.
I think the bigger issue is needing to keep on top of mainenance of the server.