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Reputation··4 min read·WillItInbox Team

IP warming schedule: ramp volume with provider evidence

Plan gradual sending increases with reputation, complaint, authentication, placement, and list-quality evidence instead of fixed-volume folklore.

IP WarmingReputationDeliverability

A new IP has no reputation. Send 50,000 messages from it on day one and major receivers will throttle, filter, or outright block — not because the mail is bad, but because the silence before it was suspicious. Warming is the discipline of teaching receivers that your traffic is wanted, one careful day at a time.

If you want the broader reputation picture while you warm, the reputation hub groups the blocklists, provider dashboards, PTR, and transport signals that affect how the ramp behaves.

The 30-day schedule

DayDaily volumeCumulative
15050
2100150
3200350
4400750
58001,550
71,500~4,000
105,000~15,000
1415,000~50,000
2150,000~200,000
30150,000+~600,000
Conservative ramp for a new IP. Multiply daily volume by ~2 if engagement holds.

What you send matters as much as how much

  • Day 1–7: send to your most engaged recipients only. Past 30-day openers are gold.
  • Day 8–14: expand to 90-day engagers. Watch for any complaint uptick.
  • Day 15–21: include 180-day engagers. Now you're testing list edge cases.
  • Day 22+: full list segments. By now, reputation should be established.

Per-receiver warming

Gmail, Microsoft, Yahoo, and Apple maintain independent reputation models. A great Gmail reputation tells you nothing about your Microsoft standing. Most ESPs let you split traffic by receiver during warming so you can ramp each at its own pace.

ReceiverSensitivityWatch metric
GmailHigh — slow rampPostmaster Tools spam rate
Microsoft (Outlook.com)Very high — slowestSNDS complaint count + JMRP
YahooMediumYahoo Sender Hub
Apple iCloudLow feedback, infer from deliveryPer-receiver bounce trend
Receiver-specific warming notes.

The three signs you're moving too fast

  1. Open rate dropping >20% day-over-day. Your mail is starting to land in spam.
  2. Complaint rate above 0.3%. Receivers are now actively penalizing your IP.
  3. Soft bounces above 5% with 4.7.x codes. The receiver is throttling — slow down immediately.

When to add a second IP

Most senders should run a single IP until they hit roughly 500,000 messages/month. Multiple IPs split your reputation and force you to warm each one — usually pointless until you have enough volume to differentiate traffic types (e.g., dedicated transactional vs marketing IPs).

Warming a domain vs an IP

Modern receivers weight domain reputation heavily — sometimes more than IP reputation. If you're moving to a new IP but keeping your sending domain, the IP warm is faster (your domain reputation carries some trust). New domain and new IP is the slowest path; budget 6–8 weeks.

Frequently asked questions

EvidenceWhat it tells youWhere to inspect
Seed placement trendWhether the controlled sample is improving, stable, or getting worse./docs/inbox-placement
Google PostmasterGmail reputation, spam rate, authentication, and compliance movement./blog/google-postmaster-tools-walkthrough
Microsoft SNDSOutlook IP traffic, complaint, trap, filter, and HELO evidence./blog/snds-microsoft-guide
List validationInvalid, risky, disposable, role, catch-all, and unknown recipient risk./tools/email-validator
Warmup evidence to collect before each volume increase.

Do not treat warmup as a fixed calendar. Increase volume only when engagement, complaints, authentication, seed samples, and provider evidence are stable. Pair the placement workflow with domain monitoring and a real-message deliverability test before each larger step.

Continue this inbox placement and reputation monitoring workflow with the commercial page, the core guide, the implementation docs.

Last updated June 13, 2026.

Sources reviewed

Factual review: June 13, 2026 by WillItInbox Editorial.

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