2.24.5.3. Configuring DMARC

DMARC is a TXT record in domain settings that determines the behavior of recipient servers when receiving messages sent from domain mailboxes.

DMARC recording added in domain settings in this form:

Options:

• v - the DMARC version. Required parameter The value is always equal DMARC1.
• p - domain rule. Required parameter It can take one of the following values:
  • none - do nothing except send reports.
  • quarantine - add emails to spam.
  • reject - reject letters.
• sp - rule for subdomains. Can take on the same values as p.
• aspf and adkim - allow you to check compliance with SPF and DKIM records. Can take values:
  • r (relaxed) - soft check.
  • s (strict) - strict compliance.
• pct - the number of letters to be filtered, in percent. For example, for pct=20 only 20% of emails will be checked.
• rua - defines the mail to which you want to send daily reports. You can specify multiple mailboxes separated by commas, for example, rua=mailto:admin@example.com,mailto:dmarc@example.com.
• ruf - defines the mail to which you want to send reports on messages that have not passed DMARC check. It is set by analogy with rua.
• fo - defines the conditions for generating reports. Can take values:
  • 0 - send a report if neither SPF nor DKIM authentication is passed. Default value.
  • 1 - send a report if one of the SPF or DKIM authentication failed.
  • d - send a report if DKIM authentication is not passed.
  • s - send a report if SPF authentication is not passed.

You can use the online DMARC generators to avoid having to manually create a record.

The correctness of the finished record can be checked using the online DMARC validators

Example domain settings with added DMARC record: