You cannot buy a sending reputation

Every part of an outbound system can be bought except the one that decides whether any of it works.

Domains can be registered this afternoon. Mailboxes can be created in an hour. SPF, DKIM and DMARC can be standing before the end of the day. A list can be bought, and the sequences can be written in a week.

None of that determines whether the mail arrives. What determines that is whether the receiving system has any history with the domain and the IP behind it, and history is the one input that cannot be purchased or accelerated.

Why it takes about three months

A brand new sending domain has no reputation at all, which receiving systems treat as closer to suspicious than to neutral. Volume has to climb slowly enough that each increase is supported by evidence of good behaviour: mail that is opened, replied to, and not marked as spam.

Push it faster and the domain is not merely throttled. It is scored, and a poor score is expensive to reverse. This is why a burnt domain is usually abandoned rather than repaired: starting again with a clean name is cheaper than rehabilitating a name the receivers have already judged.

The bar those receivers apply is no longer a matter of opinion. Google has published its requirements since February 2024 and Outlook.com since May 2025, including a spam complaint rate that must stay under 0.3%. Three complaints in a thousand messages is a tight tolerance for anyone learning on the job.

What this means commercially

It means an outbound engagement that runs for three months does not produce a result. It produces an estate that has just finished warming up, handed over at exactly the point it becomes useful.

It is the reason we do not take outbound work on a shorter term, and the reason the first three months of any build look quiet from the outside. The work in that period is real: the list is being built and verified, the infrastructure is standing up, the messages are being written against actual research. The volume is deliberately not there yet.

If a supplier offers you a fully warmed estate at volume in week two, they are either sending from somebody else's infrastructure, which makes their other clients' behaviour your problem, or they are about to burn a domain with your company's name on it.

What to ask before you buy outbound

• Whose domains are these, and who owns them at the end?
• What is the ramp, week by week, and what happens if replies are poor in week three?
• Is the list verified before sending, and how often is it re-verified?
• What is handed over, and can our own team run it without you?