What DKIM means
DKIM adds a signature that receiving servers check against a key in your DNS. It improves deliverability and makes spoofing harder. Each service that sends mail for you should be set up with its own DKIM key.
Why it matters for your website
Without DKIM, your invoices, quotes and newsletters are more likely to land in spam or be rejected. It also makes it harder for scammers to fake email from your domain. Major mailbox providers now expect bulk senders to authenticate with DKIM, so it is a basic part of reliable email.
Example
An accounting firm's client reminders keep landing in spam. After adding the DKIM record from its email provider to its DNS, the messages start reaching inboxes.
Tips
- Turn on DKIM for every service that sends email as your domain, including your newsletter tool.
- Publish the DKIM record your provider gives you exactly as written in DNS.
- Send a test email and check the headers to confirm DKIM passes.
Common mistakes
- Setting up DKIM for your main inbox but forgetting your CRM or marketing platform.
- Copying the DKIM key with extra spaces or broken lines, so it silently fails.
Questions about DKIM
What is DKIM?
DomainKeys Identified Mail: a digital signature on outgoing email that proves it was not altered and came from your domain.
Do I need both SPF and DKIM?
Yes. They check different things, and DMARC works best when both are in place.
How do I check if DKIM is working?
Send an email to an account you control and view the full message headers. Look for a DKIM result of pass.
