Yes, absolutely. I do this & have done for a decade or more. But that decade probably helps - my mail server has kept the same static IP the entire time, so ha

Yes, absolutely. I do this & have done for a decade or more. But that decade probably helps - my mail server has kept the same static IP the entire time, so has a pristine spam reputation. I added SPF a couple of years ago as otherwise Google was started to look askance at some of the emails sent from my server but I haven’t bothered with DKIM (apart from added a DKIM policy that says “I don’t do DKIM” that is). No problems so far. Where are you hosting your mailserver? If it’s on a dynamic IP on your home internet, then you’re on a hiding to nothing. Static IP on a home internet might be OK, if you can fix your reverse DNS to be something sane rather than the more usual adsl123455.isp.net or something. Google generally hates reverse DNS entries that look like consumer internet connections. If you’re hosting with AWS or another cloud provider, then I believe the only way to get an server on an IP address that doesn’t come with a terrible reputation for spam is to cycle through IP addresses until you find one that works - this is what the big mail delivery companies do I believe.