The sending layer we wished someone else had built.
sendrules is a UK company building a multi-tenant SMTP proxy for teams that have outgrown a single ESP. We don't resell sending. We don't lock you to one provider. And we publish the platform in full — the security controls, the pricing, the honest limits — so procurement doesn't have to guess.
Provider A had a bad afternoon. So did your business.
You picked an ESP three years ago. It was fine. Then their April incident dropped your transactional queue for six hours, their pricing shifted, and the deliverability team stopped picking up the phone. Every migration playbook says “switch to a backup provider” — but there’s no time to wire one up, so you don’t, so the next incident hurts as much as the last.
That’s the problem sendrules is built for. Not to replace your provider — to sit in front of the two, three, or five providers you already trust, and route around the one having a bad afternoon before anyone in your business notices.
We were tired of the workarounds.
The team behind sendrules has spent years running production email for platforms with millions of monthly recipients — the kind of workload where a single blocklist listing, a role-account send, or a warm-IP misstep costs real money by the end of the week. Every operator we knew had built the same collection of homemade tools around their ESP: a bounce-list scrubber, a manual failover playbook, an ad-hoc DMARC report reader, a Slack alert for provider incidents.
None of those tools should be homemade in 2026. sendrules is the collection of them, done properly, in one product — so the next operator doesn’t have to rebuild them from scratch.
Three principles that shape everything else.
Bring your own providers.
We do not resell sending. Every message you send through sendrules goes through your own account with your own provider — your quota, your warmed IPs, your reputation. When you leave, you take the whole relationship with you.
Observability over trust.
Every message has a route log — the rule it matched, the provider it went to, the checks that ran, the response the provider gave, the exact reason it deferred or bounced. Nothing about deliverability should be a black box, least of all when a regulator asks.
Publish what’s true.
Public pricing to five million messages a month. No hidden overage. No compliance badge we haven’t earned. No customer logo we can’t back with a named quote. If a promise isn’t on the page yet, it’s because we haven’t shipped it — not because we’re hiding it.
Registered in the United Kingdom.
sendrules is operated by a UK-based company. Our office is in London; our infrastructure is chosen so that customer traffic stays inside our data-protection perimeter. We’re happy to provide the trading name, company registration number, and VAT number in writing for procurement — write to us and we’ll send them by return.
London EC2A 4NE
United Kingdom