How to Set Up and Send Personalized Cold Emails that Convert
This free guide walks you through building a cold email system from scratch, the same way we do it at OKZest. By the end you will have:
- Separate domains and inboxes that protect your main domain
- SPF, DKIM and DMARC set up so your emails pass the Gmail, Yahoo and Outlook sender rules
- Warmed-up inboxes connected to Instantly
- A validated list of leads who fit your ideal customer
- A short email sequence with personalized text and images that gets replies
It takes about an hour to set up, then 2 to 4 weeks of warmup before you send your first campaign.
What has changed in cold email
Cold email still works, but mailbox providers are much stricter than they were a few years ago:
- Gmail and Yahoo have required SPF, DKIM, DMARC and a spam rate below 0.3% since February 2024. Since November 2025, Gmail permanently rejects mail that doesn't comply, instead of just delaying it.
- Microsoft (Outlook.com, Hotmail and Live) has rejected mail from high-volume senders without SPF, DKIM and DMARC since May 2025.
- Safe sending volumes are lower. The old advice was 50 emails per inbox per day. Today, around 30 is the recommended maximum.
This guide is built around those rules, so you don't need to know them in advance.
How the guide is organized
Follow the sections in order. Each one builds on the last.
| Step | Section | What you'll do |
|---|---|---|
| 1 | What is cold emailing? | Understand cold email, the legal basics and why personalization matters |
| 2 | Plan your sending volume | Work out how many domains and inboxes you need |
| 3 | Services and costs | See the tools we use and what they cost |
| 4 | Set up domains | Buy separate domains and redirect them to your website |
| 5 | Set up email accounts | Create inboxes in Google Workspace or Zoho Mail |
| 6 | Authenticate your domains | Add MX, SPF, DKIM and DMARC records |
| 7 | Warm up your inboxes | Connect inboxes to Instantly and build their reputation |
| 8 | Get leads | Find and validate the people you'll email |
| 9 | Write and send | Write your sequence and personalize it |
| 10 | A/B test and scale up | Improve your results and send more |
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