Lesson 4: Setting up your DKIM record for cold email

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In this lesson, you’ll learn how DKIM (DomainKeys Identified Mail) protects your emails from tampering and ensures your messages remain trustworthy.

I’ll walk you through what DKIM is, how it works, and why it’s crucial for preventing scammers from altering your emails. You’ll also get step-by-step instructions on how to set up DKIM in your domain’s DNS so your campaigns stay secure and your emails land safely in inboxes. If you’re building a technical cold email setup, understanding DKIM and managing your DNS records is essential to maintain credibility and improve deliverability.

Here is the guide on how to set up DKIM

In this lesson, you’ll learn:

• How DKIM (DomainKeys Identified Mail) works like a tamper-evident seal on your emails – if the content is altered in transit, the receiving server can detect that the message was interfered with
• Why this matters in practice: without DKIM, attackers can intercept your emails and inject malicious links, effectively hijacking your sender reputation to trick your prospects
• That DKIM is configured once per domain in your DNS settings using a private/public key pair – a one-time setup that Woodpecker’s step-by-step guides walk you through for each major provider
• How DKIM works alongside SPF as part of a layered authentication approach, with DMARC (covered in the next lesson) adding a further layer of control on top of both

Welcome to the super short lesson on DKIM.

If you just want to set this up without additional background follow the guide I linked under the lesson.

Alright, let’s cover the theory behind DKIM.

DKIM, which stands for DomainKeys Identified Mail.

It’s an essential authentication method you want to set up for all of your domains.

What DKIM basically does is to:

• put your emails in an envelope
• close it, 
• and put a seal on it. 

If the email is opened during the transfer, the seal will be broken. 

A broken seal will tell the receiving end that the email content could have been altered.

In practice that means DKIM helps to spot so-called, man in the middle attacks.

This means someone tries to catch your email and alter its contents.

An example would be a scammer trying to insert malicious links into your email.

They do this to piggyback on your reputation as a brand and trick the prospect to trust the links.

Now as a brand you most likely do not want this to happen.

So, this is what DKIM helps you to spot.

Just as SPF, DKIM is to be set up on your domain in the DNS settings. 

You will have to create two keys, a private and a public one.

Put one in your DNS settings and then turn on DKIM signing on for that domain. 

It may sound complicated but it’s a fairly simple process you only do once per domain. 

So let’s wrap things up. 

The process of how to set up DKIM changes and is different from provider to provider.

To help you get this done I will link to our step-by-step guides under this lesson.

We are updating them quite regularly. 

As mentioned this was a super short lesson.

I hope to see you in the next one where we will dive deeper into DMARC.

See you there!