First Customers (GTM)

My cold emails keep landing in spam. How do I fix deliverability?

A starting point

Deliverability is mostly technical hygiene before it's copywriting: set up SPF, DKIM, and DMARC, warm up a fresh domain slowly, and never blast hundreds from a brand-new inbox. Send from a real, monitored address, avoid link-heavy image-only emails, and keep daily volume low enough to look human. As a starting point, use a separate domain for cold outreach (not your main one) so a spam hit never poisons your team's real email.

Go deeper

Hand-picked from around the web, each with a note on why it earns your time.

3 resources 3 link-checked Read Use

Read

📄 Article
✓ Link checked Free Intermediate

Why we picked it This is the one guide that walks the full technical stack in plain language: SPF, DKIM, DMARC, domain warmup timelines, and the spam and bounce thresholds Gmail and Outlook now enforce. It is written by a cold email platform, so read the product mentions with that in mind, but the DNS and warmup fundamentals apply no matter what you send with. A good starting point if your emails are quietly landing in spam and you do not yet know why.

Email Deliverability Guide: SPF, DKIM, Warmup and Everything That Gets You to the Inbox

From Smartlead by Satwick Ghosh (Smartlead)

  • SPF, DKIM, and DMARC are three DNS records, not optional. Gmail and Outlook now reject or spam bulk senders who skip them.
  • A new sending domain needs 3 to 6 weeks of warmup before real outreach. There is no shortcut, and skipping it is the most common reason first campaigns die in spam.
  • Watch your spam complaint rate (keep it well under a fraction of a percent) and bounce rate (under 2 percent) in Google Postmaster Tools, because reputation damage is hard to undo.
Open smartlead.ai →

Use

🛠️ Tool
✓ Link checked Freemium Intermediate

Why we picked it Before you send a real campaign, this tests exactly where your email lands across Gmail, Outlook, Yahoo, and others, so you stop guessing whether the inbox or the spam folder is catching you. It also flags spam-filter scores, blocklist hits, and whether your SPF, DKIM, and DMARC are actually passing. The free check is enough to diagnose a problem before you pay for the deeper seed-list reports.

GlockApps Inbox Insight: Email Deliverability and Inbox Placement Test

From GlockApps by GlockApps

  • Shows inbox versus spam placement across the major providers, so you see the real failure, not a generic spam score.
  • Checks your sending IP against dozens of blocklists and confirms SPF, DKIM, and DMARC are passing on a real message.
  • Run it after any DNS or warmup change to confirm the fix worked instead of assuming it did.
Open glockapps.com →
🛠️ Tool
✓ Link checked Freemium Intermediate

Why we picked it Warming a new domain by hand means sending a trickle of real, replied-to emails for weeks, and this automates that slow ramp with a large network of real accounts. It starts small, grows volume gradually, and simulates opens and replies so providers learn to trust you before you send cold. Useful when you are standing up a fresh sending domain and cannot babysit the warmup yourself.

Instantly Email Warmup

From Instantly by Instantly

  • Automates the slow volume ramp a new domain needs, starting at a handful of emails a day and building over weeks.
  • Simulates genuine engagement (opens, replies, marking as important) so the domain looks trusted before real outreach begins.
  • A dashboard tracks how much of your warmup mail is reaching the inbox versus spam, so you know when you are ready to send for real.
Open instantly.ai →

People also ask

How do I write a cold email that people actually reply to? Keep it short, personal, and about them, not you. Nail a subject line that sparks curiosity, open with a specific reason you're reaching out to *th... Beginner 3 resources → How many times should I follow up before giving up on a cold prospect? More than you think, most replies come after the first email, not on it. Follow up persistently but politely, adding a little new value each time, ... Beginner 2 resources → Cold email or cold LinkedIn/DM, what works better for reaching first customers? Use whichever gets you in front of your specific buyer, and often combine them, a warm LinkedIn touch before a cold email lifts reply rates. Email ... Intermediate 2 resources → Is cold outreach even worth it, or is it just spam that hurts my brand? Done lazily it's spam; done well it's just starting a relevant conversation with someone who genuinely needs you. The difference is targeting and p... Beginner 2 resources → How do I build a targeted list of the right people to cold email? Define your ideal customer sharply, then hand-build a small list of exactly-fit prospects instead of blasting thousands. Use LinkedIn, community me... Intermediate 2 resources → What tools should I use to send and track cold outreach without spamming? For your first customers you often need nothing more than your normal inbox and a spreadsheet, send personal 1:1 emails and track replies by hand. ... Intermediate 2 resources →