Warming up a new email domain or IP means starting with a small volume of mail to your most engaged recipients and increasing it gradually over four to six weeks so that mailbox providers build a positive reputation for you. Send too much too fast from an address with no history and Gmail, Outlook and Yahoo will treat the spike as a spammer signal and route you to the junk folder. The fix is not a trick. It is a controlled ramp, sent to people who actually open your mail, on top of authentication that already passes.
Before you send a single warm-up email, confirm SPF, DKIM and DMARC are published and aligned. A perfect ramp on a broken authentication setup still fails.
Reads public DNS only. Nothing is stored unless you save the domain to an account.
Verify authentication before you send anything
Reputation is tied to a domain that providers can verify is really you. If your DKIM signature does not align with the From domain, or SPF fails on your sending IP, every warm-up email starts at a deficit and the whole exercise is wasted.
Run your domain through the checker above and confirm three things:
- SPF passes and lists the exact IPs or includes for your new sending platform. If you are near the lookup ceiling, read Fix SPF too many DNS lookups.
- DKIM is signing with a selector on your domain and the signature verifies. See How to set up DKIM if it is missing.
- DMARC is published and both SPF and DKIM align with your From domain. If alignment is your problem, Fix DKIM alignment walks through it.
Start your DMARC record at monitoring so you can watch results without blocking anything:
v=DMARC1; p=none; rua=mailto:dmarc@yourdomain.com; adkim=s; aspf=s
Keep p=none during the warm-up so you get aggregate reports and full visibility, then tighten to quarantine and reject afterward. The path from monitoring to enforcement is covered in How to move DMARC from none to reject.
The copy-paste warm-up schedule
This is a conservative ramp for a new domain or dedicated IP sending to a healthy list. Volumes are per day, per mailbox provider group. If your list is smaller, scale the numbers down but keep the same shape: slow start, gradual doubling, hold on any dip.
| Day | Daily volume | Target segment |
|---|---|---|
| 1 | 50 | Opened in last 30 days, staff and known-good |
| 2 | 100 | Opened in last 30 days |
| 3 | 250 | Opened in last 30 days |
| 4 | 500 | Opened in last 30 days |
| 5 | 1,000 | Opened in last 30 days |
| 8 | 2,000 | Opened in last 60 days |
| 10 | 4,000 | Opened in last 60 days |
| 12 | 7,500 | Opened in last 60 days |
| 15 | 12,000 | Opened in last 90 days |
| 18 | 20,000 | Opened in last 90 days |
| 22 | 35,000 | Opened in last 90 days |
| 26 | 60,000 | Opened in last 90 days |
| 30 | 100,000 | Broaden to 180 days |
| 35 | 175,000 | Full engaged list |
| 42 | Full volume | Full list |
Two rules override the table. First, never more than double from one send to the next. Second, if bounce rate climbs above 2 percent, or spam complaints cross 0.1 percent, or open rates fall off a cliff, stop increasing and hold at the last good volume for two or three sends before you resume. Providers reward a steady, believable pattern more than a fast one.
Why the segment order matters
The single biggest lever in a warm-up is who you send to first. Gmail and Outlook watch how recipients react: opens, replies, moving mail out of spam, and the absence of complaints. Starting with your most recently engaged contacts front-loads positive signals, so by the time you reach colder segments your domain already carries a good reputation. Blast the whole list on day one and the low engagement of dormant addresses drags your reputation down before it exists.
Engagement-first tactics that build reputation faster
A warm-up is really a reputation-building exercise, and reputation is built on recipient behavior, not volume. Bias every decision toward getting real engagement.
- Send to people who asked for your mail. Never buy or scrape addresses to pad a warm-up. Spam traps and unknown users during a warm-up are close to fatal.
- Lead with your best content. Order confirmations, welcome emails and genuinely useful updates get opened and clicked. Save promotional blasts for after week four.
- Ask for a reply early. A single "hit reply and tell us what you need" message generates replies, and replies are one of the strongest positive signals a mailbox provider can see.
- Keep sending consistent. Daily or every-other-day sends during the ramp beat one big weekly batch. Providers reward regular, predictable cadence.
- Clean before you start, not during. Remove role addresses, hard bounces and obviously invalid syntax up front so your warm-up list is as deliverable as possible.
- Keep every message authenticated the same way. Do not mix sending platforms mid-warm-up, because each new IP or signing setup resets part of the reputation you are building.
If mail is still landing in spam despite a clean ramp, the root cause is usually authentication or content, not volume. Why emails go to spam covers the common culprits.
How to read the warm-up in Postmaster Tools
Google Postmaster Tools is where you watch the warm-up actually work. Add your domain, verify it with the TXT record Google provides, and give it a couple of days to populate. Volume has to cross a minimum threshold before Google shows data, which is another reason the ramp matters.
Watch these dashboards:
- Domain and IP reputation. These move through Bad, Low, Medium and High. A new domain starts blank and should climb toward High as you ramp. If it drops to Low or Bad, hold volume and investigate before sending more.
- Spam rate. Keep this under 0.1 percent. The Google and Yahoo bulk sender rules treat 0.3 percent as a hard ceiling, so 0.1 percent is your working target. If it spikes, your segment or content is the problem.
- Authentication. SPF, DKIM and DMARC should all show near 100 percent pass rates. Anything lower means messages are slipping through unauthenticated and undoing your work.
- Delivery errors. A rising error rate often means a provider is starting to throttle or reject you, which is your signal to slow down.
For Outlook and Hotmail, enroll in Microsoft SNDS and JMRP to get complaint feedback and data volume by IP. The signals are the same: watch complaint rate and reputation, hold when they move the wrong way.
Meeting the bulk sender bar is not optional anymore. Google and Yahoo sender requirements explains the 2024 rules that any serious sender has to clear.
What breaks a warm-up
Most failed warm-ups share the same causes. Sending to an old, unengaged list that generates complaints. Increasing volume too fast after a few good days. Switching platforms or IPs partway through and starting the reputation clock over. Publishing SPF or DKIM incorrectly so a chunk of mail fails authentication silently. And forgetting that a shared IP pool carries the reputation of everyone on it, so on shared infrastructure you are warming the domain, not the IP.
If you are on a shared pool, focus your effort on domain reputation and content, because you do not control the IP history. On a dedicated IP, both the IP and the domain need to warm, which is exactly why the schedule above ramps slowly.
Frequently asked questions
How long does it take to warm up a new email domain?
Four to six weeks for most senders. Low-volume senders under a few thousand emails a day can reach full volume faster, while high-volume senders pushing hundreds of thousands of messages should extend the ramp to eight weeks. The right length is however long it takes to hold a High reputation and a spam rate under 0.1 percent, not a fixed number of days.
Do I warm up the domain or the IP?
Both matter, but they are separate. Domain reputation follows your From domain everywhere you send. IP reputation matters on a dedicated IP you control. On a shared IP pool your provider manages the IP reputation, so you concentrate on the domain. Either way, the ramp schedule is the same.
Can I skip the warm-up if my domain is old?
An aged domain with existing web and DNS history helps, but a domain that has never sent bulk email still has no sending reputation. You can start slightly higher and move a little faster, but you still ramp. Providers judge sending behavior, not the registration date.
What SPF, DKIM and DMARC settings should I use during warm-up?
Publish SPF and DKIM so both pass and align with your From domain, and set DMARC to p=none with a rua address so you collect aggregate reports without blocking anything. Confirm alignment in the checker before day one, then move DMARC to quarantine and reject once the warm-up is complete and reports look clean.