A new domain should send hundreds per day, not thousands. A fully warmed, healthy domain can comfortably send tens to low hundreds of thousands per day to a clean, engaged list. To go meaningfully higher in a single campaign, you need a pool of warmed domains, not a bigger single one.
Why there is a limit at all
Inbox providers cap how much they will accept from a sending domain in a given window, based on the domain's reputation and history. Push past it and they defer, throttle or reject. Your ESP cannot override this.
Realistic numbers
- Brand new domain: 50 to 500 per day for the first week.
- Two to four weeks in: a few thousand per day if engagement is good.
- Fully warmed, healthy domain: tens to low hundreds of thousands per day.
- Trying to exceed those numbers from one domain: complaints rise, opens fall, reputation slips.
How a warmed pool changes the maths
Volume is spread across many warmed, authenticated domains so each one stays well under its safe ceiling. The aggregate easily reaches millions per campaign with no single domain at risk. See One sending domain vs many.
What you should not do
- Buy a fresh domain and send 100k tomorrow. It will burn.
- Move all volume to a backup domain in a crisis. The backup burns too.
- Assume your ESP's quoted limit is the inbox's limit. It isn't.
Frequently asked questions
Can I just buy more domains?
You can buy them, but you have to warm them. A new domain with no history is a liability, not capacity.
Do dedicated IPs raise the limit?
They give you control over IP reputation, but the per-domain limit is enforced on the domain. See [Dedicated domain vs dedicated IP](/resources/guides/dedicated-domain-vs-dedicated-ip).
What about subdomains?
Subdomains inherit some of the root domain's reputation, which can help in the early days, but they still need their own warming and they share fate with the root.