Illingworth, rebuild a domain 3 times before buying a new one

Richard Illingworth posted a five step plan he says gets 9 to 12 months of sending out of a single cold email domain, and the step that is new is the rebuild rule. When a domain's reply rate halves, he says rebuild it before you buy anything, and do that up to three times before retiring it.

The structure underneath it is simple. Build each domain with three inboxes and hold each one at 15 to 20 sends a day, because, in his words, once you push them faster the domain wears out months too early. Read the domain as one number rather than three, taken as the median reply rate across its three inboxes, since a single inbox on its own jumps around too much to read.

The trigger is a 50% drop, not a wobble

Illingworth's threshold is deliberately far away. A half-percent slip is not a reason to touch anything. The domain only gets touched once its reply rate is down to half what it started on, which is the same line he drew earlier when he argued most reply rate drops are not a buying signal.

When the number does halve, the rebuild comes first. He describes it as moving the domain's inboxes onto a new admin panel so Google issues a fresh sending IP and the reputation refreshes, and he says each rebuild buys another 4 to 6 weeks of sending. Three rebuilds is the ceiling. After the third, retire the domain and swap in a fresh one.

What this is and is not

This is Illingworth's own method described on his own book of business, not an independent test. The number he leans on is scale rather than a controlled result. He has said his team has set up more than 570,000 cold email inboxes and that most of their customers now run the same inbox for 8 to 12 months, against the 3 to 4 month replacement cycle they used to run themselves. He attributes the old cycle to inboxes getting two weeks of warmup and then being pushed straight to full campaign volume overnight, the behavioural jump he says Google and Microsoft flag. That is the same argument behind his parallel warmup post from last week.

For people sending, the practical change here is the order of operations. The 15 to 20 sends a day cap and the median read are housekeeping. The rule worth writing down is that a slipping domain gets counted before it gets replaced. Before you buy another domain, check how many times you have already rebuilt the one that slipped.

Richard Illingworth

@RCIllingworth

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when it does drop 50%, rebuild it FIRST, before you buy a new domain.