DKIM stands for DomainKeys Identified Mail and is used for the authentication of an email that’s being sent. A DKIM record exists in the DNS, but it is a bit more complicated than SPF. DKIM’s advantage is that it can survive forwarding, which makes it superior to SPF and a foundation for securing your email.
You can Enable this feature in DirectAdmin easily.
First, You would need to login as a User.
In case you're a Re-seller, change the access level to User from the dropdown on top right corner.
Navigate to "Email Manager" -> "Email Accounts".
Click on the "Enable DKIM" button.
This will add two new DNS records within the DirectAdmin. You can view this by navigating to the "Account Manager" -> "DNS Management".
Be sure you're on the right Domain.
You can notice that two new
TXT Records have been added. Among them, you would need the contents of
x._domainkey which has the following format
"v=DKIM1; k=rsa; p=<encoded public key>"
If you're using CloudFlare to manage your domain's DNS, Add a new TXT Record (DKIM is configured as TXT record) with the contents of TXT record from DirectAdmin.
You can find more information about managing your DNS records in CloudFlare here.
Once everything is configured, you should be able to send signed emails.