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Set up DMARC for your business

Move from none to quarantine with a policy that protects your domain from spoofing without breaking legitimate mail.

By MrTech MelbournePublished 18 Oct 2025Updated 22 Jan 2026
01

What DMARC actually does

DMARC tells receiving servers what to do when SPF or DKIM fail — monitor, quarantine or reject. It also sends reports so you can see who is sending email using your domain name.

02

Start with monitoring

Publish a TXT record at _dmarc.yourdomain.com with v=DMARC1; p=none; rua=mailto:reports@yourdomain.com. Run in monitoring mode until you understand your legitimate senders and fix SPF/DKIM gaps.

03

Tighten the policy

Once Microsoft 365, your website forms and marketing tools all authenticate correctly, move to p=quarantine and eventually p=reject. Change one step at a time and watch the aggregate reports for surprises.

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