You can write the perfect cold email, but if it lands in spam, nobody reads it. Deliverability is the unsexy foundation that makes everything else work. AI helps you optimize content for deliverability and monitor your sender reputation.

The Deliverability Checklist

Technical Setup (Do Once)

• SPF, DKIM, DMARC — Authentication records that prove you’re a legitimate sender. If these aren’t set up, stop everything and fix them first.
• Dedicated sending domain — Don’t send cold emails from your primary domain. Use a subdomain (e.g., outreach.yourcompany.com) to protect your main domain’s reputation.
• Warm-up — New domains need 2-4 weeks of gradual sending before going full volume. Tools like Instantly and Warmbox automate this.

Content Optimization (AI Helps Here)

“Review this cold email for spam triggers: [paste email]. Identify: words/phrases that trigger spam filters, formatting issues, and anything that looks like bulk email. Suggest a rewritten version that’s deliverability-friendly.”

Common spam triggers AI catches:

• “Free,” “guarantee,” “act now” in subject lines
• Too many links (keep to 1-2 max)
• Image-heavy emails (text-only performs better for cold email)
• ALL CAPS or excessive exclamation marks
• HTML formatting (plain text delivers better)

Sending Patterns

• Volume: Start at 20-30 emails/day per domain, increase gradually
• Timing: Spread sends throughout the day (don’t blast 100 at 9 AM)
• Variety: Don’t send identical emails — personalize each one
• Bounce management: Remove bounced addresses immediately

Monitoring with AI

“Here are my email metrics for the past week: sent [X], delivered [X], opened [X], replied [X], bounced [X], marked spam [X]. Analyze my deliverability health. What’s concerning? What should I change?”

Key benchmarks:

• Delivery rate: Above 95% (below = technical issues)
• Open rate: 40-60% for cold email (below 30% = deliverability problem)
• Bounce rate: Below 3% (above = bad data)
• Spam complaints: Below 0.1% (above = content or targeting problem)

The Deliverability Checklist

Before blaming your email tool, check these basics:

• SPF, DKIM, and DMARC records — if these aren’t set up, you’re already flagged. Ask your IT team or use a tool like MXToolbox to verify.
• Warm up new domains — sending 500 emails from a fresh domain on day one guarantees the spam folder. Start with 20-30 per day and increase over 2-3 weeks.
• Clean your list quarterly — bounced emails and inactive contacts tank your sender reputation. Remove anyone who hasn’t opened in 90 days.

“Audit this cold email for deliverability red flags: [paste email]. Check for: spam trigger words, excessive links, missing personalization, and formatting issues. Suggest a rewrite that’s more likely to land in the primary inbox.”

The Reply Rate Test

Deliverability doesn’t matter if nobody replies. Test two versions of every email:

“Write two versions of this sales email: [paste]. Version A: shorter, more direct, one clear CTA. Version B: slightly longer, includes a relevant insight about their business, softer CTA. Both should avoid spam triggers and feel like a real person wrote them.”

Send 50 of each. The version with more replies wins — and replies also boost your sender reputation for future emails.

Quick Overview

Task	Without AI	With AI
Research	30-45 min	5-10 min
Email drafting	15-20 min	2-3 min
Follow-up	20-30 min	5 min

Related reading: AI Cold Email Strategies · Lavender vs Regie vs Instantly · Apollo.io Review

🛠️ Write deliverable emails: Try our Cold Email Generator — optimized for inbox placement, free.