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IP Warm-up Strategy at Scale

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janv. 15, 2026 · 6 min read

What is IP Warm-up?

When you start sending email from a new IP address, mailbox providers (Gmail, Outlook, Yahoo) don't know if you're a legitimate sender or a spammer. IP warm-up is the process of gradually increasing your sending volume to build a positive reputation.

The Golden Rules

  1. Start slow: Begin with your most engaged subscribers
  2. Increase gradually: Double volume every 2-3 days
  3. Monitor metrics: Watch bounce rates, spam complaints, and inbox placement
  4. Be consistent: Send daily during warm-up, don't skip days

A Practical Schedule

  • Day 1-2: 500 emails/day
  • Day 3-4: 1,000 emails/day
  • Day 5-6: 2,500 emails/day
  • Day 7-8: 5,000 emails/day
  • Day 9-10: 10,000 emails/day
  • Day 11-14: 25,000 emails/day
  • Day 15-21: 50,000 emails/day
  • Day 22+: Full volume

Using SendForge for Warm-up

SendForge's throttling system makes warm-up straightforward. Set daily limits per sending node and let the system handle the rest. The adaptive throttling automatically adjusts if it detects deliverability issues.

Common Mistakes

  • Sending to cold or purchased lists during warm-up
  • Skipping days or sending inconsistent volumes
  • Ignoring bounce rates above 2%
  • Not authenticating with SPF, DKIM, and DMARC first

Recovery

If your reputation takes a hit during warm-up, don't panic. Reduce volume by 50%, focus on your most engaged segment, and rebuild gradually.