Built by operators tired of fragile outbound infrastructure.
A small, technical team that automated the slow, manual work of standing up healthy sending infrastructure — and turned weeks of setup into a matter of hours.
Mailrun started from a practical frustration: building outbound infrastructure that actually lasts was too slow, too manual, and too easy to get wrong. Domains stood up by hand, authentication done piecemeal, inboxes crammed onto too few domains — and a reputation fire nobody caught until the replies stopped.
So we automated it. Domains, DNS, authentication, Azure inboxes, and a clean sequencer handoff — provisioned end to end, at a density that protects reputation instead of mortgaging it. Mailbox access that used to take weeks now takes hours, while sending volume still ramps deliberately. The unglamorous operating work runs underneath instead of landing on your team.
Our edge is execution: technical depth, operational discipline, and fast access to the people actually responsible for the system.
We’d rather look after a smaller number of customers exceptionally than chase volume. That means real people you can reach, infrastructure built with care, and quality held above quantity — on every domain, for every customer.
Small team, senior judgment.
We'd rather solve the boring infrastructure problem once, in code, than do it by hand for every customer.
No guarantees we can't keep. Low density, disciplined volume, and honest numbers beat big promises.
A small team means you reach the people who run the system, not a support maze.
We optimize for capacity that lasts — not the cheapest mailbox that burns out a quarter later.
A recent single-customer deployment runs on 2,400 domains and 24,000 inboxes — volume spread across a rotating, resting pool, not maxed per inbox.
Talk to the people who run it.
Tell us what you're building. We'll size the infrastructure and map the cleanest path to live.