Earlier quoted context omitted.
This criticism came up last time too, and I replied that I've been running my own mail server for 20 years off of a DSL line, and I have no trouble sending to anybody (that I've heard of from recipients nor MAILER-DAEMON). I have DKIM, SPF and no relaying and the only issue in recent memory was when AT&T started bouncing me for some reason. I emailed postmaster@ saying "hey wats up," and the block was removed a day o…
Do you know that your messages arrive in all cases? Not merely fail to bounce, but arrive? I help with IT for a small non-profit membership org, and the problem isn't the places that throw errors when you send, but the ones that silently accept the message without complaint and route it to /dev/null. We get through fine to Google, but the other big providers are random at best about it.
The downstream MX could be configured to then send an NDR email itself but this lands you on spam lists as "backscattering" will then send spam back to whoever owns the email address the spammer is spoofing so it's generally not done.