You've set up your new domain, configured SPF, DKIM, and DMARC, and you're ready to start sending cold emails. But if you start blasting hundreds of emails from day one, you'll end up in spam faster than you can say "deliverability."
Email warmup is the process of gradually building your domain's reputation with email service providers. Think of it like building credit: you start small, prove you're trustworthy, and gradually earn the ability to send more.
Why Warmup Matters
Email providers like Gmail, Outlook, and others track sender behavior meticulously. They look at:
- Sending volume patterns: New domains sending high volumes are suspicious
- Engagement metrics: Open rates, replies, and interactions
- Spam complaints: Even a few can tank your reputation
- Bounce rates: High bounces indicate poor list quality
A proper warmup teaches email providers that you're a legitimate sender who sends emails people want to receive.
The 4-Week Warmup Schedule
Here's our proven warmup schedule for new domains:
Week 1: Foundation (10-20 emails/day)
Send only to people you know will engage: colleagues, existing contacts, friends. Focus on getting replies and positive engagement. No cold outreach yet.
Week 2: Expansion (30-50 emails/day)
Continue warm contacts but start mixing in some cold outreach. Target your highest-probability prospects. Keep cold volume under 50% of total.
Week 3: Growth (75-100 emails/day)
Increase cold outreach percentage. Monitor deliverability metrics closely. If you see issues, scale back. Continue warm sending for engagement signals.
Week 4: Cruising (100-150 emails/day)
Reach your target sending volume. Domain should have established reputation. Continue monitoring and never exceed 200/day per inbox.
Using Warmup Tools
Automated warmup tools can accelerate the process by simulating positive engagement. They work by:
- Sending emails to a network of real inboxes
- Having those inboxes open, reply, and mark as "not spam"
- Creating consistent positive engagement signals
Popular tools include Instantly, Lemwarm, Warmbox, and Mailreach. We recommend using one alongside manual warmup for best results.
Pro Tip: Never Stop Warming
Even after your initial warmup, keep the warmup tool running at a low level (10-20 emails/day). This maintains your reputation during slow periods and protects against sudden drops in engagement.
Signs Your Warmup Is Working
- Inbox placement: Test emails land in primary inbox, not spam
- Open rates: 40%+ on warm contacts, 30%+ on cold
- Google Postmaster: Domain reputation shows "High"
- No blacklists: Clean checks on MXToolbox
Common Warmup Mistakes
- Rushing the process: Patience is essential; 4 weeks minimum
- Ignoring engagement: Volume without engagement hurts reputation
- Inconsistent sending: Daily consistency matters more than volume
- Poor list quality: Sending to invalid emails during warmup is devastating
- No monitoring: Check metrics daily during warmup
Skip the Learning Curve
Our team handles email infrastructure setup and warmup for all our clients. Start with warmed, ready-to-send domains.
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