Tool · Calculator
Sending capacity calculator.
Updated 18 October 2026
A summary of this page, not a result.
Sending setup · in your accounts
Set up before the first send.
- A separate secondary domainNever your main domain
- SPF, DKIM and DMARCAuthenticated before the first send
- Warm-upA gradual ramp, not a switch
- Sending volumeSet in writing
- AccountsThe domains and inboxes are yours
Sending capacity is the number of inboxes you have, multiplied by what each one sends. The second number, how many different people that reaches, is smaller than most people expect because every person gets a sequence, not one email. Put your own figures in below. Nothing you type leaves this page.
This calculator does the arithmetic and nothing else. It will not tell you a safe volume, because that depends on the age and history of each domain. How to choose one is in how many cold emails per day is safe.
Your numbers
The values filled in are examples. Replace them with yours.
How it's worked out
- Inboxes = domains × inboxes per domain.
- Emails per day = inboxes × emails per inbox per day.
- Emails per week = emails per day × sending days per week.
- Emails per month = emails per week × 52 ÷ 12.
- People reached per month = emails per month ÷ emails per person across the sequence.
Reply rates quoted for cold email count different things. Before you compare yours, read why the published figures disagree.
What to do with the result
Write the volume down per inbox and per domain before sending starts, and check placement every week. That is how we run it in every engagement: how sending infrastructure is set up, and Terms §6.