Set up DKIM

In this article, we will give you a deep insight into DKIM (DomainKeys Identified Mail) and show you step by step how to set up DKIM in your CleverReach account:

What is DKIM?

The abbreviation DKIM stands for DomainKeys Identified Mail and helps to significantly improve the deliverability of mailings by signing them using two corresponding digital keys.

Each time a mailing is sent, the receiving server checks whether the e-mail may be delivered or not. DKIM is based on asymmetric encryption, which ensures that a mailing really comes from the sender that is displayed and that the content has not been changed in between.

  • The first key is stored and published on your DNS server (public key).
  • The second key is only known to the sender (private key).

The first public part of the key, is placed as a TXT record in your domain of your provider's / host's DNS server, which serves as the sender address. The other private part of this key is used to generate an individual DKIM signature for each email. This signature is automatically inserted into the email header.

When a receiving server detects such a header, it searches for the public part of the key. In doing so, it queries the Domain Name System (DNS) for the TXT record.

If both keys match, the newsletter is delivered. The receiving server thus knows that the e-mail has not been modified and originates from the specified sender.

When depositing your domain, we automatically create a DNS entry as a TXT record for you, which you must have deposited with your domain provider/provider. Please note that the public key must not be removed.

Requirements for you as a CleverReach user

  1. Do not use a free e-mail service:
    If you use a free email service such as Gmail or Yahoo for your sender email address, we strongly recommend that you switch to an email address from a private domain (e.g. a domain that you use for your work or for your website).
    If you do not yet have your own domain, you can purchase one from a domain host such as Ionos .
  2. With more than 5000 e-mails sent per day:
    As of February 1, 2024, Gmail and Yahoo require custom authentication for anyone who sends more than 5,000 emails to Gmail or Yahoo addresses within 24 hours.
    To guarantee that your emails continue to be delivered, you should therefore set up DKIM in your account.

    Note: Even if you send fewer than 5000 emails per day, we still recommend setting up a DKIM entry to increase the deliverability of your emails.

  3. Make sure the domain is the same
    Make sure that the sender email address from which you send emails matches the domain for which you have set up DKIM or is a subdomain of it.

What happens if you do not fullfill the requirements?

Changes can take time. We will therefore temporarily replace your sender address for you so that it meets the new requirements of Gmail and Yahoo and your emails reach your recipients as usual.

Replacing your address has no effect on replies from your recipients. These will be sent automatically to your original e-mail address.

Your sender address could look like this after automatic replacement:


original e-mail address
E-mail address replaced by us

Note: Nevertheless, we recommend that you set up DKIM in your account to increase your deliverability. Your recipients could possibly mark your mailing as spam because the sender address we have replaced is unknown to them.

Set up DKIM in CleverReach

Follow these steps to add a new domain to use DKIM:

  1. Click the profile icon in the upper right corner.

  2. Open My Account.

  3. Under the menu item, select Settings > DKIM.

  4. Click Add domain.

You can optionally add the selector.
The selector is used to identify the DKIM public key details of the domain.

Once you have successfully created the DKIM key in the account, the next step is to adjust the DNS record for the domain or have your domain provider/provider adjust it:

Customize DNS record for your domain

  1. Click on the action button ••• right at the end of your domain entry.
  2. Select Show DNS settings.

  3. Copy the TXT record.

  4. Add the TXT record in the DNS settings of your domain provider. After up to 48 hours, the DKIM domain is set up.

Here you can find information about customizing your DNS record with various domain providers/providers:

  • You can make the DNS setting in the customer login. After login, select the menu items Domains > Domain management.
    In the domain overview you will find a gear to the right of the respective domain. Please select this one.
    In the domain overview you will find a gear to the right of the respective domain. Please select this one.
    For more information, take a look at the step-by-step guide at Strato

  • With a TXT record you can specify any additional information about your domain. This information is stored in the DNS zone.

    Add TXT record

    You can add a TXT record in the Control Center.

    • Click the gear icon under Actions for the domain you want, and then click DNS.

    • Click Add Record and select TXT under Type.

    • In the Host name field, specify the desired host, for example, www or @.
      The @ character is used as a wildcard in this case and ensures that the domain is called with www and all subdomains.

    • In the Value field, type the text you want.
      For example, a security token from Google to confirm your domain or subdomain.

    • Optional: Select the desired TTL (Time-To-Live).By default, your settings are active immediately.

    • Click Save.
      The TXT record is added.

      For more information, check out the step-by-step guide at 1&1 (Ionos).
  • Create a TXT Record

    With a TXT record you can specify any additional information about your domain. This information is stored in the DNS zone.
    1. Select a zone to which you want to add records.
    2. Click the Records button in the top navigation.
    3. Select the TXT Record type from the drop-down menu.
    4. Enter the host (use @ for root): Subdomain for which you want to create the entry, including the domain name.
    5. Enter the content you want the hostname to contain.
    6. Select TTL: time to live - validity period of the DNS record.
    7. When you have filled in all the fields, click the Add record button.
    8. The DNS entry is created and displayed in the list below.

      For more information, check out this step-by-step guide or this article at Hetzner.
  • Make DNS entry for domain

    To do this, select the menu item Product Management > Domain Services > Administration > Edit Nameserver / DNS Records. This interface allows you to make your own changes to the name server records for the selected domain. You can define hostnames (A records), aliases (CNAMEs), text entries (TXT), as well as e-mail exchangers (MX records). Insert the TXT record there.

    For more information, check out this step-by-step guide at HostEurope.
  • Log in to KAS (technical administration) and click Tools -> DNS Settings.
    Edit the domain for which you want to make changes, and then click Create new DNS record. At TYPE select "TXT", PRIO remains at "0". In the DATA field please enter the desired entry.
    Then click on the save button and the entry is made. The entry is now displayed in the table.

    For more information, check out this step-by-step guide at All-Inkl.

Activate DKIM

As a final step, activate your DKIM key:

  1. Click on the action button ••• right at the end of your domain entry.

  2. Select Verify.

  3. Now a checkbox appears under the status entry if the setup was successful. The status automatically changes to active and your DKIM key is successfully set up for the domain: 

Help & Support

If you have any questions or need assistance, please contact our service team. They’ll be there for you.