Illingworth says one $10 domain can carry 60 inboxes
The spec sits behind a comment gate, and the same operator lists 10 inboxes on one domain as a spam cause.
Richard Illingworth says he runs 60 sending inboxes off a single $10 root domain, and that the build delivers "the same deliverability as 60 separate ones" at one tenth of the cost. He says he has used the setup across more than 2,000 cold email infrastructure builds.
The mechanism, as he describes it, is root and branch. Rather than buying 60 domains, you buy one and split inboxes across subdomains, with what he calls an internal build spec covering subdomain counts, inbox counts, DNS and daily send config. He cites a 5,000-account client that sent 1.8 million emails at 99.7% inbox health, and frames the cost swing as a $2,000 domain bill turning into $10, with a burned domain becoming a $12 non-event.
What is actually published
Not much. The numbers are in the post, the spec is not. To get the blueprint you comment "BRANCH" and follow, and he DMs it over. He also offers a 28-day complimentary infrastructure package of 60 free inboxes wired to his monitoring platform. So the 99.7% figure is his own reporting on his own client, with no breakdown of send period, sender reputation at the start, or how inbox health was measured.
There is a tension worth naming. In a separate post the same week, Illingworth listed seven reasons cold email lands in spam, and reason three is cramming 10 inboxes onto one domain, which he says gets the lot flagged at once. His position is presumably that subdomains change the blast radius, but the free post does not explain where the line sits. He does say the blueprint names four places you should not try this, which is at least an admission that the pattern breaks somewhere.
you crammed 10 inboxes onto one domain. that pattern gets the lot flagged at once.
For people sending
Consolidating 60 inboxes onto one registration is a concentration bet. If the root gets flagged, the thing you saved money on is the thing you lose. That may be fine at $10 a replacement, and the arithmetic is the real argument here, not the deliverability claim.
The same seven reasons post repeats his other numbers, including raw Apollo lists coming back 50-65% valid and Google to Microsoft replies at 0.3% against 4% Google to Google. Treat the subdomain split as unverified until someone outside his client base posts numbers.
99% of all cold emailers i’ve ever spoken to overpay for their setup.
Know what is landing before you burn another domain
One email a day. Under three minutes. What the operators found out yesterday.