Email Warmup for a New Domain: The 6-Week Schedule That Works

Email warmup for a new domain is not optional — it’s the difference between your emails arriving in the inbox and being systematically spam-foldered or rejected by the receiving mail servers. Mailbox providers assign reputation scores to IP addresses and domains. New domains start at zero. Warmup is the process of building that reputation score by demonstrating consistent, engaged-upon sending behaviour.

This post gives you a concrete 6-week schedule, explains the signals you should monitor, and describes how DexcyJet’s infrastructure handles warmup mechanics.

Why New Domains Need Warmup

Mailbox providers maintain a signal that can be roughly described as “trust”. For a new domain, that signal doesn’t exist — and absence of trust is treated as suspicious. Receiving servers throttle, defer, and spam-folder messages from new domains until they’ve seen enough evidence that the domain is a legitimate, wanted sender.

Specifically, receiving servers watch:

• Volume trajectory: Does this domain send a consistent, gradually increasing volume? (Trusted sender) Or does it appear at full volume on day one? (Suspicious)
• Bounce rate: Does the domain send to valid addresses? High early bounces = list quality problem = spam signal
• Engagement rate: Do recipients open and click? High engagement = wanted mail
• Spam complaints: Is anyone marking this mail as spam?

A warmup schedule is designed to establish positive signals in all four dimensions before you hit your full sending volume.

The 6-Week Warmup Schedule

This schedule assumes you’re starting from a brand-new domain and IP address (or a previously unused IP). Adjust for shared IP pools — if using DexcyJet’s shared sending infrastructure, warmup happens at the pool level and your individual warmup requirements are less strict, though still relevant for your domain reputation.

Volume ramp

Week	Daily volume	Total weekly
Week 1	50–100/day	350–700
Week 2	200–500/day	1,400–3,500
Week 3	1,000–2,000/day	7,000–14,000
Week 4	5,000–10,000/day	35,000–70,000
Week 5	20,000–40,000/day	140,000–280,000
Week 6	50,000–100,000/day	350,000–700,000

After week 6, you can approach full volume — though always ramp gradually rather than jumping from 100k/day to 500k/day in a single send.

Engagement-first sending

The most important rule: send warmup volume to your most engaged subscribers first. This means:

• In weeks 1–2, only email people who opened or clicked in the last 30 days
• In weeks 3–4, expand to 90-day engagers
• In weeks 5–6, add 180-day engagers
• Only include cold or old subscribers after your domain reputation is established

The logic: engagement signals (opens, clicks) during warmup are your strongest positive reputation signal. A 40% open rate on 500 emails sends a strong “this is wanted mail” signal to Gmail. A 5% open rate on 50,000 emails is a much weaker signal even if the absolute numbers are similar.

Per-mailbox-provider distribution

Don’t send all warmup volume to one provider. Spread across Gmail, Outlook, Yahoo, and others. Reputation is per-provider — building Gmail reputation doesn’t automatically build Outlook reputation.

A rough distribution for an Indian audience:

• Gmail: 60–70% of volume
• Outlook/Hotmail: 15–20%
• Yahoo/Rediff: 5–10%
• Others (Samsung, Apple iCloud, etc.): 5–10%

What to Monitor During Warmup

Google Postmaster Tools

Register your sending domain at postmaster.google.com. This gives you:

• Domain reputation score: Good / Medium / Low / Bad
• IP reputation score (if dedicated IP)
• Spam rate: The fraction of your mail Gmail is marking as spam
• Authentication status: SPF, DKIM, DMARC compliance rates

Watch the domain reputation score daily during warmup. It should start at “Low” and move to “Medium” by end of week 2, “High” by week 4 if your engagement rates are healthy.

If it drops to “Bad” at any point, stop sending and diagnose. Sending through a “Bad” reputation signal will not fix itself — it compounds.

Bounce rates

During warmup, hard bounce rate should stay below 0.5%. If it’s higher, you’re sending to too many invalid addresses. Pull back, clean your list, and restart the warmup from a lower volume point.

Deferred delivery

Deferred messages (soft bounces that the provider retries) are normal during warmup — providers throttle new senders. Monitor your deferred rate. A 5–10% deferral rate is normal in week 1. By week 4, it should be below 2%.

DexcyJet logs delivery status per message, including deferral timestamps and retry counts, in the campaign delivery report.

Common Warmup Mistakes

Sending promotional content before the domain is warm

Warmup sends should ideally be your highest-value content — not your most promotional. Recipients are more likely to open and engage with genuinely useful content. A newsletter or product update is better warmup material than a discount offer.

Using a completely fresh list

If you’re migrating from another platform, your list has history. Don’t treat migration as a warmup restart unless you’re also changing your sending domain. If you’re keeping the same domain, your reputation (good or bad) moves with the domain.

Stopping and restarting

Consistency matters. A domain that sends 5,000 emails/day for 3 weeks, then nothing for 2 weeks, then tries to send 50,000/day looks erratic. Inbox providers trust consistent senders. Don’t take long breaks during warmup.

Shared IP warmup confusion

If you’re on a shared IP pool (DexcyJet’s default for lower-volume plans), the IP is already warmed — it’s shared with other senders. You’re warming your domain reputation, not the IP. This is an easier task, but still requires the same engagement-first approach and the same bounce/complaint vigilance.

Setting Up Warmup in DexcyJet

DexcyJet’s warmup mode lets you define a volume cap per day and a segment of your most-engaged subscribers to target first. Configure it from the Domain settings panel:

curl -X PATCH https://jet.dexcy.in/api/v1/sending_domains/dom_01j... \
  -H "Authorization: Bearer $DEXCYJET_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "warmup_enabled": true,
    "warmup_daily_limit": 500,
    "warmup_engagement_filter": "last_90_days"
  }'

DexcyJet will automatically cap outgoing volume at 500/day for the domain and prioritise your most-engaged subscribers when campaigns are sent. Increase the limit weekly as your metrics stay healthy.

For the full picture of deliverability beyond warmup, read our post on 12 tactics to improve email deliverability. And for the authentication foundations you need before warming up, read SPF, DKIM, and DMARC setup.

Try DexcyJet: Built-in domain warmup mode with engagement-first sending and daily volume caps. Start free — no card required.