Illingworth posts the six sending rules behind his agency

Richard Illingworth published the six standard operating procedures he says took his cold email agency to 170k a month. Four of them govern sending, two govern the shop itself.

The sending rules

Before any domain goes live it has to pass SPF, DKIM, DMARC and MX checks. No inbox goes past 20 emails a day, and no domain carries more than three inboxes. Warmup runs at least 14 days, and nothing launches until the account hits a 70% health score. Mailboxes are split 70/30 or 50/50 across Google and Outlook so that, in his words, one filter change can't take everything down.

The other two are operational rather than technical. Every new client gets set up off the same written checklist, and the steps for pulling each client's numbers are written down so reports still go out when someone is away.

What this is and is not

This is a stated policy, not a test. Illingworth does not say how many domains, inboxes or sends sit behind the rules, and the 170k a month figure is his own with no breakdown. Nothing in the post shows what happens at 25 emails an inbox, or at four inboxes a domain, or at a 60% health score. The numbers are the lines his agency draws, not thresholds anyone measured a cliff at.

They are also conservative by the standards of this niche. Twenty a day per inbox with a three-inbox cap means 60 sends per domain per day at the ceiling, which is a lot of infrastructure for any serious volume. The two-week warmup floor and the health score gate push the cost of a launch further out again. If you run leaner than that today and your placement is fine, this post is not evidence you are wrong, it is evidence of what one agency decided it was willing to risk.

The provider split is the rule that travels best, because it is insurance rather than a limit. Splitting mailboxes across Google and Outlook means a filtering change at one provider takes part of your sending capacity instead of all of it. Illingworth has previously argued for subdomain sending with the root domain kept silent, which sits in the same category of structural hedging.

Richard Illingworth

@RCIllingworth

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so one filter change can't take everything down