Cloud Server for Email
infrastructure@cloudserverforemail.com · +372 602 3545 · cloudserverforemail.com
IP Warming Checklist
For New Dedicated Sending IP Addresses
Version 2026-04 · Cloud Server for Email
Pre-Warming Preparation
- Sending domain is a subdomain (not primary domain) — e.g., mail.yourdomain.com or send.yourdomain.com
- SPF record configured and includes all new sending IPs (~all or -all)
- DKIM configured: 2048-bit RSA key, selector published in DNS, signing verified via test email
- DMARC configured: p=none minimum with rua reporting address active
- PTR (rDNS) records set for all new IPs, matching PowerMTA EHLO hostname
- Google Postmaster Tools: sending domain verified and monitoring active
- Microsoft SNDS: sending IPs registered at SNDS portal
- Blacklist pre-check: all new IPs clean on Spamhaus ZEN, Barracuda, SORBS
- Bounce server (IMAP) configured and processing test bounces correctly
- Unsubscribe link functioning and global suppression list active
- Initial engagement segment prepared: subscribers who opened/clicked in last 30 days
- PowerMTA warming schedule configured (max-msg-rate per ISP per week)
Week 1–2: Careful Start (Target: 500–2,000 emails/day)
- Send ONLY to highest-engagement subscribers (30-day openers, engagement >30%)
- Check Postmaster Tools domain reputation the morning after each send
- Check SNDS IP status for each sending IP
- Deferral rate target: <5% per ISP — if above, do not increase volume
- Spam rate target: <0.05% — if above, pause and investigate list segment
- Review PowerMTA accounting log: check dsnDiag for unexpected deferral patterns
- Do NOT send to inactive subscribers (90+ days since last open)
- Do NOT exceed warming volume limits set in PowerMTA config
Week 3–4: Volume Build (Target: 5,000–15,000 emails/day)
- Expand to 60-day engagers if Week 1–2 metrics were clean
- Monitor deferral rate per ISP daily — should remain <5%
- Check Gmail domain reputation: should show Medium or High
- Check SNDS: all IPs should show Green
- Review FBL data if FBL enrollment is active
- Bounce rate target: <2% hard bounce per campaign
Week 5–8: Ramp to Production
- Expand to 90-day engagers, then full active list progressively
- Increase volume 50–100% per week maximum if metrics are clean
- Gmail reputation should be High by week 6–8
- SNDS should be consistently Green for all IPs
- Configure full production PowerMTA domain blocks (remove warming volume limits)
- Run re-engagement campaign to identify inactive subscribers before warming completes
Post-Warming Verification (Week 9+)
- Gmail domain reputation: High sustained for 2+ weeks
- Gmail spam rate: <0.10% consistently
- SNDS: all IPs Green
- Deferral rate across all ISPs: <5%
- FBL complaint rate: <0.3 per 1,000
- DMARC policy: advance to p=quarantine with 5% rollout
- Blacklist check: all IPs clean
- Document final production domain block parameters for reference
Critical: Never advance warming volume if any metric exceeds thresholds. Premature volume increases during warming can cause permanent IP reputation damage that takes 4–6 additional weeks to recover.
Managed Warming: Cloud Server for Email manages IP warming for all infrastructure clients. This checklist reflects our internal warming protocol. Contact infrastructure@cloudserverforemail.com for managed warming services.