I’m aware most ISPs do not allow for port 25 to be open for email use outside of business licenses, but at what level is that controlled? Can I get around that by owning my own router? Owning my own modem or ONT? Or is this just a thing they mystically control further up the pipeline that a relative layman such as myself can’t get around?
It’s all on their end, though I’ve had limited success asking nicely, it’s just there so businesses don’t just order the cheaper plan and then they have to deal with all the extra traffic and support for many users. Just assuring them that I am just running as a single user my own email server they were cool with it on small local ISPs bigger corps won’t give you the time of day on that issue.