Inbound email is working on the secondsite community but not on the first site, looking at the logs it shows incoming email is being picked up by the SMTP server but there’s nothing in the discourse email logs to show it was even received much less processed or rejected.
I don’t see any settings differences between these two communities that would cause this, and I’m not sure where else to look for clues about what to do to fix it.
I’ve moved this topic to Installation > Hosting since it appears to be about tinkering with a self-hosted Discourse setup. I also added unsupported-install because it clearly involves a setup that does not follow the official install guide.