You sent 100 cold emails. 0 responses. Most never arrived - they were filtered as spam because your domain has zero sender reputation.
The problem: Without warmup, only 10-20% of cold emails reach inboxes. With proper warmup, deliverability reaches 85-95%.
Email warmup gradually builds sender reputation over 4-8 weeks by mimicking normal email behavior: gradual volume increase, consistent daily sending, positive engagement, and domain authentication.
Recommended tool: WarmupInbox automates email warmup using a network of 20,000+ real inboxes. Features include reputation monitoring, spam rate checks, Gmail Primary Inbox placement, and email alerts. Pricing starts at $15/month per inbox (annual) with a 7-day free trial. Try WarmupInbox →
Step 1: Set Up DNS Records
Required before sending. Email providers use these to verify your domain is legitimate.
SPF: Add TXT record - Name: @, Value: v=spf1 include:_spf.google.com ~all (Google Workspace) or v=spf1 include:spf.protection.outlook.com ~all (Microsoft 365)
DKIM:
- Google Workspace: Admin Console → Apps → Google Workspace → Gmail → Authenticate email → Generate key → Add TXT record
- Microsoft 365: Admin Center → Settings → Mail → Manage DNS → Add provided records
DMARC: Add TXT record - Name: _dmarc, Value: v=DMARC1; p=none; rua=mailto:your-email@yourdomain.com (start with p=none, move to p=quarantine after warmup)
Verify: MXToolbox | Video: Stewart Gauld's tutorial
Step 2: Create Email Accounts
Setup: 3 email accounts per domain. Use US-sounding names (firstname.lastname@yourdomain.com), add professional signatures, set up forwarding.
Important: Use Google Workspace or Microsoft 365. Free services have poor deliverability.
Step 3: Warmup Schedule
Week 1-2 (Manual):
- Days 1-3: 2-3 emails/day per account - email people you know, request replies, subscribe to newsletters
- Days 4-7: 5-7 emails/day - mix internal/external emails
- Days 8-14: 10-15 emails/day - build email threads, ensure positive engagement
Week 3-8 (Automated):
- Week 3-4: 20-30 emails/day per account
- Week 5-6: 40-50 emails/day per account
- Week 7-8: 60-80 emails/day per account
After 8 weeks: Domain ready for cold email campaigns.
Step 4: Monitor Reputation
Metrics: Deliverability (aim 85%+), spam complaints (under 0.1%), bounce rate (under 2%), reply rate (higher = better)
Tools: Mail-tester.com | MXToolbox | Sender Score | Google Postmaster Tools
Best Practices
Do: Start 4-8 weeks early, send daily (consistency), prioritize engagement, use separate domain, keep DNS updated, gradually increase volume
Avoid: Sending too fast, skipping DNS setup, free email services, buying lists, stopping warmup after campaigns, mixing accounts, ignoring spam complaints
Email Warmup Tools
Automated warmup tools save time and improve results by handling engagement at scale.
WarmupInbox uses a network of 20,000+ real inboxes to improve deliverability. Features include sender reputation monitoring, spam rate checks, blacklist detection, Gmail Primary Inbox placement, and email alerts when reputation drops. Uses real user inboxes (not fake accounts) and everything is automated without affecting your inbox.
Pricing: $15/month per inbox (annual) or $19/month, with a 7-day free trial and no credit card required.
Start warmup: Try WarmupInbox free trial →
FAQ
How long? Minimum 4 weeks, recommended 6-8 weeks.
Subdomains? Yes, they need their own warmup.
Emails marked spam? Reduce volume 50%, focus on engagement, review DNS, pause 1-2 days.
Speed up? Not recommended - triggers spam filters and damages reputation.
What Happens Without Warmup?
90%+ emails go to spam, domain blacklisting, wasted time, months to recover. Example: 500 emails without warmup = 8% deliverability. After 2 months warmup = 92% deliverability.
Start Your Email Warmup
- Set up DNS records (SPF, DKIM, DMARC)
- Create 3 email accounts on separate domain
- Begin manual warmup (2-3 emails/day)
- Gradually increase over 8 weeks
- Monitor metrics
- Maintain consistent sending
LinkDR automates cold email campaigns with domain warmup built-in. Start free trial →
