Cold email is still one of the fastest ways for founders and sales teams to put their product in front of the right people. No algorithms, no ad spend, no waiting for inbound to compound. You write a message, it lands in someone's inbox, and if it's relevant, they reply. At scale, a well-run cold email system generates pipeline for a fraction of what paid channels cost.
But most cold email systems break before the first message sends — not because the copy is weak, but because the infrastructure was never set up right. Missing DNS records, unwarmed domains, and misconfigured sending platforms mean your emails hit spam on day one.
Claude handles the entire infrastructure setup so you can go from zero to a fully operational sending system in an afternoon.
How Claude Helps You Build This
Instead of researching domain best practices, manually generating DNS records, and guessing whether your warmup is working, Claude executes the full infrastructure workflow for you. It calculates capacity, generates DNS records, configures your sending platform, schedules warmup, and audits deliverability before you go live.
To do this, Claude uses two skills:
- setup-outreach-campaign — configures Smartlead or Instantly, handles mailbox allocation, sending schedules, and volume limits.
- cold-email — covers domain strategy, warmup protocols, volume scaling rules, and deliverability hygiene.
You provide your target sending volume and your sending platform. Claude does the rest.
The Workflow
Step 1: Calculate your sending capacity
Tell Claude how many emails you want to send per day and which platform you're using. Claude works backward from your target using the cold-email skill:
- 30 emails per day per mailbox is the safe ceiling
- 300 emails/day = 10 mailboxes across 3+ domains
- 150/day = 5 mailboxes across 2 domains
You get a capacity plan with exact domain and mailbox counts plus a cost estimate before you buy anything.
Step 2: Source dedicated sending domains
Claude generates domain name variations based on your company name — professional alternatives that keep your primary domain isolated. For each candidate, it checks blacklist status and domain history to make sure you're not buying a burned reputation.
You purchase the clean ones at $10–15 each. Never use your main company domain for cold email — one spam complaint affects every email your company sends.
Step 3: Generate and verify DNS records
Claude generates the exact SPF, DKIM, and DMARC records your mail provider requires using the cold-email skill — not generic templates, but actual TXT records with your specific values.
- Claude outputs the records, ready to copy
- You paste them into your DNS settings (the only manual step — 2 minutes per domain)
- Claude runs a verification check to confirm propagation
- It flags problems: duplicate SPF records, missing DKIM selectors, loose DMARC policies
All three records are non-negotiable. Miss any one and your deliverability drops before you send a single email.
Step 4: Set up mailboxes and connect your sending platform
Claude creates a mailbox allocation plan and configures your platform using the setup-outreach-campaign skill:
- Email addresses mapped across domains
- Daily sending limits set to 30 per mailbox
- Sending windows matched to prospects' business hours
- Spacing configured to avoid suspicious burst patterns
It connects each mailbox to your Smartlead or Instantly workspace and verifies the connections are live.
Step 5: Schedule and monitor warmup
No cold sending for 2–4 weeks. Claude initiates warmup for every mailbox — starting at 2–3 emails per day, ramping gradually. Using the cold-email skill, it sets up:
- Warmup configuration in your sending platform
- Monitoring for inbox placement rate, warmup scores, and bounce rates
- Alerts that flag any mailbox falling below threshold
The target: inbox placement above 95% before any cold sending begins.
Step 6: Run a deliverability audit before going live
Claude runs a final audit across every domain and mailbox:
- DNS records still propagated correctly
- Warmup scores meeting the 95% threshold
- Each domain clean against major blacklists (Spamhaus, Barracuda, SORBS)
- Sending limits correctly configured
The output is a go/no-go checklist. Green across the board means you're ready to load a list and launch. Red flags come with specific remediation steps.
One founder who followed this exact infrastructure-first approach — aged domains, verified DNS, four weeks of warmup — sent 15,400 emails and landed 83 customers at roughly $400 total cost.
What You Walk Away With
After running this workflow, you have:
- Dedicated sending domains — configured and isolated from your primary domain
- Verified DNS records — SPF, DKIM, and DMARC confirmed across every domain
- Warmed mailboxes — 95%+ inbox placement, ready for cold sending
- Configured sending platform — correct volume limits, sending windows, and mailbox connections
- A deliverability baseline — documented audit results you can reference when scaling
Why This Matters
Most cold email advice skips straight to subject lines and personalization. That's optimizing the last mile when the first mile is broken. Get the infrastructure right and your emails reach inboxes. Reach inboxes and your copy gets a chance to work.
This workflow gives you the foundation. Once it's live, you're ready for the next step: building a prospect list that won't burn the infrastructure you just set up.
Build your cold email infrastructure with Gooseworks