It's very uneven, and which domain(s) you have trouble with will not necessarily be the same as anyone else's problem domains. I also self-host, no mailing lists, personal mail only, and my one and only deliverability problem is AT&T. Google? OK. Comcast? OK. Charter? OK. Hotmail? OK. Any @sbcglobal.net address, or anything else associated with SBC d/b/a AT&T? Fahgeddaboudit. I can check the public DNSBLs, and there's no problem. I can jump through AT&T's hoops, and get their automated replies, and next week I try to send to a person on AT&T and find I'm back on their secret blacklist.