Originally decided to merge intake and publish onto the exact same hostname (reads.aiste.io serving both the GitHub Pages CNAME and Postmark’s inbound MX record). That turned out to be DNS-invalid: a CNAME record cannot coexist with any other record (including MX) at the same name — GitHub Pages subdomains specifically require a CNAME, and GitHub’s docs only support CNAME for subdomains (no A-record alternative), so that route isn’t available either. Decided instead: reads.aiste.io keeps its CNAME to GitHub Pages untouched, and intake moves one level deeper to mail.reads.aiste.io, which gets its own MX record to inbound.postmarkapp.com. Different exact hostnames, so no DNS conflict — while still nesting intake under the reads.aiste.io name rather than an unrelated-looking sibling subdomain, preserving the spirit of the original merge decision.