Illingworth and Shields put replies upstream of copy
Two senders spent the week arguing that inbox placement is arithmetic, not writing.
Richard Illingworth told cold emailers to stop trying to write better copy until they have checked their infrastructure, saying that get it wrong and up to 75% of sends land in spam. He put a credential behind it, claiming he has set up 570,000+ cold email inboxes. His framing is blunt about the order of operations, that copy is the last thing costing you replies, because an email sitting in spam is never read.
That 75% number is one operator's assertion and he publishes no test behind it, no sample, no before and after. We covered the same claim earlier. What is checkable is the arithmetic he sells alongside it.
The volume formula
Illingworth also published an infrastructure blueprint built around a daily volume formula, with worked examples for 250, 500, 1,000, 2,000 and 10,000 emails per day. The logic is a chain. Your target sets the number of inboxes, the number of inboxes sets the number of domains, and warmup only decides when you are allowed to send that much. The blueprint also covers SPF, DKIM, DMARC and MX setup per domain, a four week warmup schedule, list hygiene aimed at keeping bounces under 1.5%, and reserve infrastructure so scaling does not stall.
His advice to anyone about to buy inboxes is to run the formula first, because it costs two minutes and saves rebuilding the setup in six weeks.
Shields shows the same math with a client
James Shields answered a client who asked why 120 inboxes were needed instead of his own Gmail, and the answer was the same arithmetic. Shields says Gmail and Outlook watch per inbox volume, so he caps every inbox at 20 sends a day. The client wanted 2,400 emails a day, so 2,400 divided by 20 gives 120 inboxes, spread across 40 domains at three inboxes each, none of them the client's real domain. If one burns, it gets binned and swapped. That setup ran about 50,000 emails a month and returned 18 booked calls in the first 30 days.
For people sending, the two posts are not independent confirmation of anything. Illingworth sells infrastructure and Shields sells a done for you service, and both have an interest in you believing the problem is upstream of your copy. The part you can verify yourself is the division. Decide your daily target, pick a per inbox cap you trust, and see whether the inbox count you already bought actually supports it.
go much past 30 cold emails a day and they start pushing you to spam
the copy is the LAST thing costing you replies.
Know what is landing before you burn another domain
One email a day. Under three minutes. What the operators found out yesterday.