DKIM (DomainKeys Identified Mail) is an email sender verification technology which adds a digital signature related to the domain name. The presence of this signature confirms that the email has really been sent from the indicated address.
The digital signature is designed to prove email authenticity and protects against spam and phishing. Emails are provided with a digital signature on the mail server of the email sender. The email sender cannot add the signature themselves, unless they are the administrator of the server from which the email is being sent.
The use of the DKIM technology implies some software modifications to the mail servers and clients. To correctly display the digital signature, DKIM technology support is required from both parties – not just from the email recipient, but also the email sender.
If your domain is delegated to Yandex, all emails are automatically provided with the digital signature. This is indicated by an icon next to the domain name. If the domain is not delegated to Yandex, automatic DKIM activation is not guaranteed and the procedure must be performed manually.
Add a special TXT record to the DNS of your domain. To find this record, go to the domain page and click in the right column of the “DKIM digital signature” section on the Display record content link.
DKIM will be activated within 24 hours. After this, all emails will get a digital signature automatically.