Then you realize the true pain of having a near-zero reputation when trying to email anything to people on Gmail, Yahoo, Live, etc, etc. Expect to go to spam even if you have DKIM, SPF, and no relaying. If anyone actually knows the secret to not having your own mail-server's mail go to spam on these bigger systems, please tell, I've Googled it for years with no success.
Agreed! I've been running my own mail server for 20+ years, and I would not recommend that anybody do this on a lark. Deliverability to GMail is a huge problem for me and has been for years. I even asked friends at Google to find out what the story was. All I got back is that the mail group was so careful/paranoid it wouldn't talk to them either. I would long ago have switched over to a vendor, but I use qmail-style…
I don't have a problem setting up a full email server, but I don't want to babysit it for just one person using it. I have too many real life obligations these days to try and fix the mess if a problem would arise.