DKIM – (DomainKeys Identified Mail)
Use DKIM to prove your identity with a digital signature for your emails and newsletters
DKIM (short for „DomainKeys Identified Mail“) adds a digital signature to your emails. This proves the authenticity of the sender. It verifies that an email comes directly from the stated sender and that it has not been changed or falsified. Our CleverReach customers can rely on the fact that all outgoing emails from CleverReach® are automatically marked with DKIM signatures.
But what if you’re sending your emails via your own domain or those of your agency’s customers? In that case, you can generate your own domain key and add it to the sending domain.
1. How does DKIM work?
To successfully set up DKIM for your domain, it’s essential to understand how it works:
DKIM is based on asymmetrical encryption. The first step is to generate a digital key pair that corresponds to each other when sending emails.
- The first key is the Public Key; it will be added to your DNS server and published.
- The second key is the Private Key, which is only known by the sender.
The first public part of this key is placed as a TXT record in your domain of the DNS server of your provider / host, which serves as the sender address.
The private part of the key is used to generate an individual DKIM signature for each email.* The signature is automatically inserted in the email header.
When sending your email, the receiving server recognizes the individual DKIM signature in the header. That’s the signal to look for the public key. The receiving server checks with the Domain Name System (DNS) of your domain for the public TXT data record.
If the keys match, the mail is delivered. The receiving server then “knows” that the email actually comes from the stated sender and has not been changed.
* For those who want to know in detail: The signature code is generated from a combination of the email content and the private key using a security algorithm.
2. Setting up DKIM in the domain
The first step for using DKIM is to add your new domain to your account. Navigate to My Account – Settings – DKIM Domains.
By adding your domain, we automatically create a DNS entry for you as a TXT record, which you have to make available to your domain provider.
You can also add the selector. The selector identifies the public DKIM key details of the domain. It is a kind of prefix to the public key. It is inserted in the DKIM signature with the tag „s=“. Very often, “default” is used for the selector. The txt entry of the DKIM signature email header then contains “s=default”.
You have successfully added the DKIM key to your account? For your next step, adjust the DNS entry for the domain or have your domain provider adjust the DNS entry for you.
To get the DNS entry as TXT record for your domain, click on “i”.
If you need any help setting up the DNS entry, please contact your domain provider/host.
3. Checking the DKIM entry
Have you made the DKIM entry in your domain? Now it takes one or two days until the settings become effective.
To check whether the entry has been added correctly, use our DKIM Record Check. Simply click on the Check button after the setup. The system checks in the background if everything has been set up correctly and whether the DKIM signature is working.
- If the setup was not verified, please wait 24-48 hours before you try the verification again.
- If the verification was successful, the DKIM domain is active and DKIM has been set up successfully.
If you no longer want to use DKIM, you can delete your domain. Please note that as soon as you remove the domain from your account, your emails are no longer signed with this domain.
- If you need any help setting up the DNS entry, please contact your domain provider. The CleverReach support cannot assist you in this case.
- The feature is not available in our Lite plan.
4. DKIM email authentication for higher delivery rates
DKIM – amongst SPF and DMARC – is one of the most important protocols for the authentication of email senders. It makes email delivery more secure.
When checking the DKIM keys, email clients recognize whether the email actually comes from the stated sender and whether it has been manipulated. If the private and public keys match, the email usually ends up in the mailbox – and your recipient can look forward to great offers and news.
If the two keys do not match, the email client assumes that the mail has been manipulated and the mail is not delivered.
DKIM is also a security measure for the sender, as they can assume that they end up on the whitelist with a DKIM signature and are listed as a reputable sender. As a result, they can enjoy high delivery rates and do not have to fear that their newsletter will be sorted out as spam or, in the worst case, that their sender address may get blocked. This would have a negative effect on your reputation as a sender.
5. Setting up the DNS entry
What you can do in your CleverReach account:
- Create DKIM key
- Generate DNS entry
The DNS entry generated by CleverReach® is a TXT record. This DNS record must now be added to your domain.
You can find the instructions for adding DNS entries at your respective web hosting provider. Since the steps are different for each provider, we unfortunately cannot offer you any help at this point.
It can take up to 48 hours before the DKIM signature is effective. Test the entry as described above under point 3 or use an external DKIM Record Check.
Get started for free with CleverReach®
- up to 250 recipients
- and send up to 1.000 emails per month for free!
Our Lite Plan has no limited running-term. There is no setup fee and no contractual obligations.
If you need to send more mailings you can choose between our prepaid plan and our flat rate. Our price plan calculator will tell you which plan is the best for you!