Outbound
Cold Email Volume & Inbox Calculator
How many inboxes and domains you need to send your target volume safely.
Free cold email volume calculator. Enter your target daily sends and per-inbox limit to see how many inboxes and domains you need to scale cold email without burning deliverability.
Volume scales by adding inboxes, not cranking one. 30–50/inbox/day after warm-up is the sustainable ceiling; spread inboxes across domains to contain reputation risk.
How it works
Enter your target volume
Input how many cold emails per day you want to send.
Set the safe per-inbox limit
Enter the daily send limit per inbox (30–50 after warm-up is sustainable) and how many inboxes you run per domain.
See the infrastructure you need
The calculator returns the number of inboxes and domains required, plus your monthly sending capacity.
Frequently asked
How many cold emails can one inbox send per day?
After a 3–4 week warm-up, 30–50 per inbox per day is the sustainable ceiling. Pushing more through a single inbox looks like spam to mailbox providers and risks the domain. Volume scales by adding inboxes, not cranking one.
How many inboxes do I need for cold email?
Divide your target daily volume by the safe per-inbox limit. To send 300/day at 40/inbox, you need about 8 inboxes — spread across multiple domains. This calculator does that math, including how many domains to spread them over.
Why spread inboxes across domains?
To contain reputation risk. If one domain's reputation gets damaged, you don't want all your sending capacity on it. Running a few inboxes per domain across several domains keeps a single problem from taking down your whole operation.
Should I send from my main domain?
No — always use dedicated sending domains separate from your primary. A burned reputation should cost you a throwaway domain, not your company's real email. Protecting the primary domain is a core reason to plan inbox/domain infrastructure up front.