Free tool · no sign-up
Email warm-up calculator
Short answerA new domain usually needs two to four weeks of warm-up, starting at 2-5 emails a day per mailbox and growing to 30-50. Enter your domain's age and target volume to get a day-by-day plan and the number of mailboxes you need.
Your plan
24 days to reach 40 emails a day per mailbox
New (under 1 month) · starts at 3 a day · then about 30 campaign emails plus ~10 background warm-up a day
| Week | Days | Emails per day, per mailbox |
|---|---|---|
| Week 1 | Days 1-7 | 3-6 |
| Week 2 | Days 8-14 | 7-13 |
| Week 3 | Days 15-21 | 15-29 |
| Week 4 | Days 22-24 | 32-40 |
Start this plan automatically. RoxInbox adjusts it every day from real spam signals.
Start this plan freeLookups run in your browser through public DNS-over-HTTPS resolvers (Cloudflare, then Google). We don't store what you check. Privacy
How to use it
Reading the result
- 1
Pick your domain's state
New, young, aged or recovering. Aged domains with a clean history ramp fastest.
- 2
Set a per-mailbox target
30-50 emails a day is typical for cold email; the calculator caps at 50.
- 3
Add your daily goal
Enter the total campaign emails you want to send per day to see how many mailboxes and domains you need.
- 4
Follow the plan, then watch signals
Real ramps should slow down on spam signals. RoxInbox adjusts the curve daily for you.
- Warm-up schedule
- A warm-up schedule is the daily sending volume for a new or cold mailbox, rising gradually from a few emails a day to its working volume, so that mailbox providers build trust before campaigns start. More about Warm-up schedule
FAQ
Warm-up calculator questions
How long does it take to warm up a new domain?
Two to four weeks for most new domains. Aged domains with a clean history can be ready in under two weeks; domains recovering from a block often take four weeks or more.
How many emails per day should a new domain send?
Start at 2-5 emails a day per mailbox and increase by roughly 10-20% a day, holding steady if spam placement rises. Most cold-email mailboxes plateau at 30-50 a day.
How many mailboxes do I need?
Divide your daily campaign goal by the campaign volume per mailbox. Keeping about a quarter of each mailbox's volume for background warm-up, a 40-a-day mailbox sends about 30 campaign emails.
Should I keep warming after the ramp?
Yes. Background warm-up at about 20-30% of volume keeps engagement signals steady during campaigns.
Go deeper: The complete guide to email warm-up. Fix it for good with email warm-up.
More free tools
Check the rest of your setup.
Domain health check
SPF, DKIM, DMARC, MX and PTR in one check
SPF checker
Validate your SPF record and lookup count
DKIM checker
Find and verify a DKIM selector
DMARC checker
Read your DMARC policy and reporting
Blacklist checker
Is your domain or IP on a blocklist?
DMARC generator
Build a DMARC record step by step
SPF generator
Build an SPF record for your senders