How to warm up a new domain for cold email
Step-by-step warm-up for a new cold email domain: 14-day timeline, daily ramp, what campaign-ready means, volume limits, and the pre-warmed alternative with real costs.
The short answer
Plan on at least 14 days of warm-up before sending cold email from a brand-new domain. On EmailPal a mailbox is marked campaign-ready after 14 days of warming (about 7 days of ramp on an aged domain, and the flag is informational rather than a lock), warming costs $0.60 per inbox per month, and you then start cold sending at a few emails a day per mailbox rather than at full volume. The alternative is leasing pre-warmed inboxes at $3 per month each, which can send 15 cold emails a day from day one with a 90-day minimum term.
Buy a separate sending domain, put 2 to 5 mailboxes on it, confirm SPF, DKIM and DMARC on public DNS, turn warming on, and send no cold mail for 14 days. After that, start at about 5 cold emails per mailbox per day and step up to 15 over three weeks while the list stays verified and warming keeps running. Warming builds sending history; it does not fix authentication, a bad list or a burned domain. If you cannot wait, pre-warmed inboxes skip the ramp for $3 per month each, in exchange for a 90-day minimum, a 15-a-day cap and a domain you do not own.
How it works, step by step
Step 1
Buy a separate sending domain
Do not send cold email from your company’s main domain. Register a lookalike or secondary domain; EmailPal domains start from $1 one-time, and aged unwarmed domains start from $19. Name it like a real business, and avoid words such as outreach, blast or bulk.
Step 2
Create 2 to 5 mailboxes on the domain
Put two to five mailboxes on each domain rather than twenty, so that no single name carries all the volume and one filtered domain does not stop the whole campaign. Use real-looking first and last names. Starter includes 50 mailboxes at $69 per month and extra mailboxes are $1 each.
Step 3
Confirm authentication on public DNS
SPF, DKIM and DMARC must pass before warming starts. EmailPal writes SPF with -all, DKIM (RSA-2048 and Ed25519) and DMARC p=reject on domains it hosts and re-verifies them against public resolvers. If you bring your own domain, check the records from a public resolver.
Step 4
Turn warming on with the right profile
Use the standard profile for a domain with no history: it starts at about 2 warming messages a day and reaches about 20 a day around day 14. Use the accelerated profile only for an aged domain or a mailbox that has already been sending: it starts at about 5 a day and reaches the same level in about a week. Warming is $0.60 per inbox per month.
POST /api/public/v1/warmingbashcurl -X POST https://www.emailpal.io/api/public/v1/warming \ -H "Authorization: Bearer $EMAILPAL_API_KEY" \ -H "Content-Type: application/json" \ -d '{"action": "enable", "mailbox_ids": ["mbx_2c81f0", "mbx_2c81f1"]}'Step 5
Send no cold email for the first 14 days
Let the ramp run. Do not add campaign volume on top of it, because that is the most common self-inflicted failure. Use the 14 days to verify the list, write a plain first email and set up the sequencer. Check state and inbox rate every few days; if a mailbox goes into Slow-Ramp or is blocked, fix the cause rather than pushing through.
GET /api/public/v1/warming?mailbox_id=mbx_2c81f0bashcurl "https://www.emailpal.io/api/public/v1/warming?mailbox_id=mbx_2c81f0" \ -H "Authorization: Bearer $EMAILPAL_API_KEY"Step 6
Check campaign-ready and the inbox rate together
campaign_ready turns true after 14 days of warming. It is a calendar flag, so read inbox_rate and health_score beside it: a mailbox that spent 14 days landing in spam is past the flag and still not healthy. EmailPal does not block you from sending before the flag or after a poor inbox rate; that decision is yours.
Step 7
Start cold sending low and step up
Begin at about 5 cold emails per mailbox per day for the first week, about 10 in the second, and up to 15 from the third week if bounces stay near zero and replies arrive. This schedule is conservative general guidance, not an EmailPal rule. Keep warming on while you send; warming messages do not count toward the cold cap.
Step 8
Scale with mailboxes, not per-mailbox volume
When you need more volume, add mailboxes across more domains. Ten mailboxes at 15 a day is 150 cold emails a day. EmailPal’s hard ceiling on any mailbox is 100 a day, and it is a ceiling, not a target.
01
What warming does and does not do
Warming gives a new mailbox a small, rising history of real conversations, so that Gmail, Microsoft and Yahoo have something to score other than nothing. EmailPal runs that ramp against real accounts at Gmail, Yahoo and AOL, records where each message lands, and shows the inbox rate beside the mailbox. It includes spam rescue, which tries to pull a thread back toward the inbox when a seed account reports spam, and weekend throttling, so Saturday and Sunday look like quieter days rather than a weekday blast.
Warming does not fix missing or misaligned SPF, DKIM or DMARC, a list full of catch-alls and disabled mailboxes, identical copy sent in bulk, or a domain that is already on a blocklist. It does not erase history: restarting warming does not reset a domain’s reputation. And it does not guarantee inbox placement at any provider. It improves your starting position.
02
The timeline
Days 1 to 14: warming only. On the standard profile the planned curve is roughly 2, 2, 3, 3, 4, 5, 6, 7, 9, 10, 12, 15, 18, 20 warming messages a day. The curve is concave on purpose so the steepest relative increases do not fall in week one. Days 15 to 21: campaign-ready, cold sending at about 5 a day per mailbox. Days 22 to 28: about 10 a day. From day 29: up to 15 a day if the list is clean. Warming continues in the background throughout.
On an aged domain with the accelerated profile (starts at about 5 a day) the ramp reaches the ceiling in about 7 days. In EmailPal the campaign-ready flag is still set at 14 days of warming on every profile except no-ramp, which is flagged immediately because that profile exists for mailboxes that already have sending history. Sending on the no-ramp profile on a genuinely new mailbox is the pattern that gets a domain filtered.
Campaign-ready is informational
EmailPal marks a mailbox campaign-ready after 14 days of warming and shows its measured inbox rate next to it. Neither blocks sending: the campaign picker labels the mailbox “Warming up” and the launch checklist warns that sending cold now may hurt deliverability, and that is all it does.
03
Daily volume guidance
There are two separate numbers. Warming volume is what EmailPal’s network sends and answers on the mailbox’s behalf, and it tops out at 20 messages a day. Cold volume is what your sequencer sends to prospects. Warming messages do not count toward the cold cap.
For cold volume, the pre-warmed cap is 15 a day per inbox, the credential export recommends 15, and the mail server enforces a hard ceiling of 100 a day on any mailbox. Start well below 15 on a mailbox that has just been warmed. Verify every list before it goes out: EmailPal pauses a campaign when hard bounces pass 5% after at least 200 sends, but a bounce storm in the first week can undo the ramp long before that.
04
Alternative: pre-warmed inboxes
EmailPal pre-warmed inboxes are leased at $3 per inbox per month. They sit on domains aged 90 days or more, are listed only after a finished warming ramp (14 days or more), carry the measured inbox rate on the listing before you pay, can send 15 cold emails a day from day one, and keep warming running for free, so you do not pay the $0.60 on top. They do not use up an included mailbox slot.
The tradeoffs are real. There is a 90-day minimum term, and releasing before day 90 does not cancel the remaining minimum. The cap is 15 cold emails a day and cannot be raised. EmailPal owns the domain: you lease mailboxes, you do not transfer the name, and you do not get Google Postmaster access to it. The mailboxes are hosted SMTP and IMAP, not a Google Workspace or Microsoft 365 seat. And a measured inbox rate from warming is not a guarantee for your campaign: a scraped list and a heavy HTML pitch can still land in spam.
05
Cost math with real prices
Warming ten mailboxes you own is 10 x $0.60 = $6 per month, or $18 over 90 days, and twenty mailboxes is $12 per month. Ten pre-warmed inboxes are 10 x $3 = $30 per month, a $90 minimum commitment over the 90-day term, which is $72 more than warming the same ten mailboxes for three months. These figures exclude the plan fee (Starter is $69 per month with 50 mailboxes included) and the domain price.
What the extra $72 buys is time: waiting 14 days with ten mailboxes at 15 a day delays 10 x 14 x 15 = 2,100 cold sends. Whether that is worth paying for depends on how quickly a campaign has to start. If you can wait two weeks, warming your own mailboxes is cheaper and gives you the domain. If a campaign cannot wait, leasing is the faster option.
Limits, prices and names, in one table
The figures this page relies on, so you do not have to hunt for them.
| Minimum warm-up before cold email | 14 daysFresh domain, standard profile. About 7 days of ramp on an aged domain. |
| Campaign-ready flag | After 14 days of warmingImmediate on the no-ramp profile. Informational, not a lock. |
| Warming ramp, standard profile | About 2 per day, rising to about 20Warming messages only. They do not count toward the cold cap. |
| Warming ramp, accelerated profile | About 5 per day, reaching about 20 in a weekFor aged domains or mailboxes already sending. |
| Warming price | $0.60/inbox/moReal Gmail, Yahoo and AOL accounts. Same price for hosted, Gmail, Outlook or your own server. |
| Pre-warmed inbox | $3/mo, 90-day minimumDomains aged 90+ days. 15 cold emails a day from day one. Warming included. |
| Cold volume per mailbox | 15/day recommended; 100/day hard ceilingPre-warmed inboxes are capped at 15/day. |
| Warming 10 owned mailboxes for 90 days | $18Plan fee and domain not included. |
| 10 pre-warmed inboxes for the 90-day minimum | $90Plan fee not included. |
| Domain | From $1 one-timeAged unwarmed domains from $19 one-time. |
| Mailboxes per domain | 2 to 5 |
| Campaign bounce auto-pause | 5% default after 200 sendsAdjustable from 0.5% to 5%. |
Checked against the product and the API on . Plans and limits change, so confirm in the docs before you build on them.
This is not for you if
- You need to send to a full list tomorrow. Warming a fresh domain takes at least 14 days; pre-warmed inboxes are the only fast option and cap at 15 a day each.
- You want to own the domain you send from and also skip the wait. Pre-warmed inboxes are leased on domains EmailPal owns.
- You expect warming to guarantee inbox placement. It builds history; it does not control how a provider scores your list or copy.
- Your domain is already burned or blocklisted. Warming does not erase reputation. Retire the name instead.
- You need a Google Workspace or Microsoft 365 seat on a pre-warmed domain. EmailPal pre-warmed inboxes are hosted SMTP and IMAP mailboxes.
Common questions
How long does it take to warm up a new domain for cold email?
At least 14 days. EmailPal marks a mailbox campaign-ready after 14 days of warming, and the standard ramp on a fresh domain starts at about 2 warming messages a day. An aged domain on the accelerated profile reaches its ramp ceiling in about 7 days, and the flag still comes at 14 days of warming on every profile except no-ramp.
Can I send cold emails before the mailbox is campaign-ready?
Yes, nothing in EmailPal blocks it. The campaign picker labels the mailbox “Warming up” and the launch checklist warns that sending cold now may hurt deliverability. The safer course is to wait until day 14 and keep early volume very low.
How many cold emails per day can a new mailbox send?
Start at about 5 per day after the 14-day warm-up and step up to 15 over three weeks. That schedule is conservative guidance. EmailPal caps pre-warmed inboxes at 15 a day and enforces a hard ceiling of 100 a day on any mailbox. Add mailboxes for more volume rather than raising the number.
Do warm-up emails count toward my daily sending limit?
No. Warming traffic is separate from the cold-email cap, which counts campaign messages and replies you send from the Unibox. Warming also keeps running while you send campaigns.
What is the difference between warming and pre-warmed inboxes?
Warming at $0.60 per inbox per month is a ramp you run on a mailbox you own or create, and you wait for it. Pre-warmed inboxes at $3 per month are leased mailboxes on domains aged 90 days or more whose ramp already finished, with a measured inbox rate on the listing, 15 cold emails a day from day one and a 90-day minimum term.
Does warming fix a domain that already lands in spam?
No. Warming cannot fix missing authentication, a dirty list, or a domain that is already blocklisted or has earned complaints, and restarting it does not reset reputation. For a burned domain the realistic fix is a new name with clean authentication and a verified list.
Build it on infrastructure that holds up
Domains, mailboxes, warming and verification over one REST API and MCP server, with the sequencer, Unibox and CRM on every plan.
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