I setup my own mail server last year and shortly gave up on the idea. Setting the server up isn't the problem. The problem is keeping your IP off of all the major blacklists. I wasn't even sending out mass emails and 30%+ of my email would never be delivered. I had to constantly check to see if my IP addresses were on the various spam lists (and fight to get my IPs off) and I just got tired of it. Companies like Goog…
I've been running a postfix for years (since 2008ish) and never once checked or worried about blacklists. My 3 users haven't reported any problems at all.
What if they missed emails they never knew about in the first place? What if they tried to contact someone and just assumed they've been ignored? Unless you know you're not on blacklists, you should be worried at least a bit.