Mailbox and domain calculator
Estimate mailboxes and domains needed for a weekly first-touch target.
Your inputs stay in this browser. No account needed.
Your result
Add your inputs, or try the example, to see your result here.
Domain counts depend on your own configuration and deliverability policy.
How to use this tool
- Calculate net message slots after warmup and reserve expected follow-ups.
- Divide the weekly target by first-touch capacity per mailbox, rounding up.
- Divide mailboxes by mailboxes per domain, rounding up.
What the result tells you
- Domain counts depend on your own configuration and deliverability policy.
- The estimate assumes a steady campaign after sequence ramp-up.