I get my IP through work, but another way of obtaining one would be subscribing to a business account with a regular ISP. Normally, this also allows you to set a reverse DNS. You will likely have to pay more for your Internet, but considering that you won't have to pay for any cloud service anymore, you will probably still come out ahead and gain a huge amount of sovereignty over your computing. A VPS could be an option, but many (cheap ones) may have tainted IPs or outright filter the SMTP port.