Definition of DKIM
DomainKeys Identified Mail (DKIM) is your newsletter's digital signature that proves emails actually came from you, not some sketchy impersonator. It works by adding an invisible cryptographic signature that receiving servers can verify. Your DKIM record in your DNS proves you're legit so you can skip the spam folder.
Why you should care
DKIM directly impacts your newsletter's deliverability, which means it affects whether your content even reaches subscribers. Without it, email providers increasingly view your messages with suspicion, sending them straight to the junk folder where they'll die a lonely death without ever being read.
Quick win:
- Check if your DKIM is set-up by sending a test email to a Gmail account
- Then, click the three dots next to the reply button, select "Show original"
- Look for "DKIM: 'pass'" in the authentication results
If it doesn't pass, don't sweat it. Setting it up with your email service provider (ESP) is pretty quick. More emails landing in inboxes means more opportunities for click-throughs growth and conversion rate success.
DKIM is that critical, unsexy behind-the-scenes tech that makes all your creative newsletter efforts actually matter by ensuring they reach real humans instead of spam filters.
⚠️ BTW, if you just set up a new domain you may have to wait a couple of days before you can create a DKIM record on your email host.
Some resources we rely on
Ask Claude for help with DKIM
Copy and paste this prompt into Claude or the AI of your choice. Be sure to tweak the context for your situation.
<goal>
Set up proper DKIM authentication for my newsletter to improve deliverability and inbox placement rates.
</goal>
<context>
* I run a newsletter using [ESP NAME]
* My domain is hosted with [DNS PROVIDER]
* Current deliverability issues: [DESCRIBE ANY PROBLEMS]
* Technical comfort level: [BEGINNER/INTERMEDIATE/ADVANCED]
</context>
<output>
Please provide:
* Step-by-step DKIM configuration instructions for my specific ESP and DNS provider
* Required DNS records with clear explanation of each field
* Verification methods to confirm DKIM is working properly
* Troubleshooting guide for common DKIM issues
</output>
<example>
DNS Record Format Example:
- Record type: TXT
- Name/Host: selector._domainkey.yourdomain.com
- Value: v=DKIM1; k=rsa; p=MIGfMA0GCSqGSIb3DQEBAQUAA4GNADCBiQ...
- TTL: 3600
Verification Test:
1. Send test email to Gmail account
2. View original message (three dots menu)
3. Look for "DKIM: 'pass'" in authentication results section
</example>
<guardrails>
* Instructions must work with standard DNS management interfaces
* No advanced command line requirements if possible
* Focus only on DKIM (not SPF or DMARC yet)
* Prioritize security without compromising ease of setup
* Respect ESP's recommended settings over generic advice
</guardrails>