What is DMARC?

When you want to protect your domain

If someone tries to send fake messages pretending to be your domain, receiving servers need a rule for what to do.

SPF and DKIM help check messages. DMARC tells receivers what policy you want when those checks fail.

Quick answer

DMARC is a policy published in DNS.

It tells receiving mail servers what they should do when a message that claims to be from your domain does not pass authentication.

The policy can be:

• p=none: monitor and authenticate, without asking receivers to block;
• p=quarantine: ask receivers to place suspicious messages in spam or quarantine;
• p=reject: ask receivers to reject failing messages.

DMARC is not always the first step

Before using a strict policy, you should know who sends email for your domain.

If you set p=reject too early, legitimate email from a newsletter, invoice system, CRM or website form may be blocked.

That is why PRIMARI.NET normally recommends starting with:

v=DMARC1; p=none

It is a cautious starting point.

What happens without DMARC?

Email can still work, but the domain is less protected against impersonation.

You may see:

• receivers trusting your messages less;
• less control over fake messages using your domain;
• difficulty applying a clear anti-impersonation policy;
• problems with receivers that expect stronger authentication.

DMARC is not essential on day one, but it helps complete the setup.

When to use quarantine or reject

quarantine and reject can be useful, but they should be enabled carefully.

First, check that all legitimate senders for the domain are covered by SPF or DKIM.

This includes normal mail, website forms, newsletters, invoices and any other service sending as your domain.

How PRIMARI.NET handles it

PRIMARI.NET can prepare a safe initial policy:

v=DMARC1; p=none

This policy does not ask receivers to reject messages. It gives the domain a clean base.

If you later want to move to quarantine or reject, it is best to review every legitimate sender first.

When to contact PRIMARI.NET

Contact us if you want to protect your domain from impersonation, if you are unsure which DMARC policy you have, or if you want to move from none to a stricter policy safely.