4.4.6. Configure DMARC

Before configuring DMARC, first configure SPF and DKIM, as they are required for DMARC to work.

DMARC is a special TXT record that is added to domain settings like this:

Subdomain	Type	Data
`_dmarc`	`TXT`	`v=DMARC1; p=none; rua=mailto:admin@example.com`

The data field contains parameters that define the behavior of recipient servers when receiving messages sent from domain mailboxes.

v (required parameter) — DMARC version. The value is always equal to DMARC1.
p (required parameter) — rule for the main domain. Possible values:
- none — do nothing but send reports.
- quarantine — put messages into spam.
- reject — reject messages.
sp — rule for subdomains. The values are similar to p.
aspf and adkim — check compliance with SPF and DKIM records. Possible values:
- r (relaxed) — soft check.
- s (strict) — strict compliance.
pct — percentage of messages for which filtering should be applied. For example, pct=20 means to check 20% of messages.
rua — address of the mailbox to which daily reports should be sent. You can specify several mailboxes separated by commas, for example, rua=mailto:admin@example.com,mailto:dmarc@example.com.
ruf — address of the mailbox to which to send reports about messages that failed DMARC check. It is set similarly to rua.
fo — report generation conditions. Possible values:
- 0 — send a report if both SPF and DKIM authentication fail (default value).
- 1 — send a report if one of the authentications is not passed: SPF or DKIM.
- d — send a report if DKIM authentication is not passed.
- s — send a report if SPF authentication is not passed.

Instead of compiling the record manually, online DMARC generators can be used:

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

(3)

Configure