With Sendinblue, you can customize your senders' DKIM signature with your domain name, whether your campaigns are sent via Sendinblue shared IP addresses or via dedicated IP addresses.
To do this, go to Settings and click on Configure in the Your Senders box.
Or, click on your company name and select Senders & IP.
Click on Domains and select Add a new domain.
The sender editing window will then open. By default, your emails are signed by Sendinblue or the domain name associated with your dedicated IP address.
To customize your DKIM signature, check the box: I would like to use this domain name to sign my emails.
Now enter the domain name you wish to use to sign your emails (in our example, we have entered the subdomain tutorial.sendinblue.com). When you click on the save button, a pop-up will appear with the DNS entries to be configured.
Once the configuration is complete, a green check will appear next to the DKIM, SPF and Verify Code keys (and possibly DMARC).
Now click on DONE.
From now on the emails sent by this sender will be signed by your own domain name!