DMARC (Domain-based Message Authentication,
Reporting and Conformance) is a technology to extend the capabilities of
the SPF and DKIM sender
policies. The DMARC policy defines how the receiver should treat email
messages depending on the results of DKIM and SPF checking. This
technology is based on the rules specified in the sender’s DNS zone.
In Plesk, you can set up a DMARC policy for outgoing mail
by specifying rules in a DNS record.
In Plesk for Linux and Plesk for Windows that uses SmarterMail,
DMARC also checks incoming mail by default.
To set up a custom DMARC policy for outgoing mail:
Go to Tools & Settings > DNS Template and edit the DNS records
related to the DMARC policy. These DNS records are always present in the
server-wide DNS template. (By contrast, DNS records
related to DKIM are added to DNS zones of
individual domains when you activate DKIM on the domain.)
For example, the Plesk default DMARC policy is defined in the following
record:
_dmarc.<domain>. TXT v=DMARC1; p=none
This policy recommends that the receiving mail server does not delete
messages even if they failed checking. You can specify a stricter
policy. However, note that the receiving server is free to apply its own
policy to incoming mail.
Hosting customers can edit the policies for individual domains.
For information on DMARC, including policy notations, refer to
https://datatracker.ietf.org/doc/rfc7489/.
To disable DMARC to check incoming mail:
- Go to Tools & Settings > Mail Server Settings (under
“Mail”). - In the DMARC section, clear the “Enable DMARC to check incoming
mail” checkbox and then click OK.
