DMARC Setup for Sending Email

DMARC (Domain-based Message Authentication, Reporting and Conformance) protects your domain from spoofing by telling receiving email servers what to do when messages fail authentication. Your DMARC policy determines whether failing messages are delivered, quarantined, or rejected. CloudMailin automatically collects and parses the reports that show how your policy is working.

CloudMailin Handles the Prerequisites

DMARC requires both SPF and DKIM to be configured. CloudMailin automatically:

  • Signs all messages with DKIM - Your 2048-bit DKIM key is automatically applied to every outbound message
  • Configures SPF via CNAME - SPF is automatically set up when you add the required DNS records
  • Aligns authentication - Both DKIM and SPF align with your sending domain

You just need to add the DMARC DNS record and choose your policy to protect your domain.

Beta Feature: DMARC report collection and dashboard is currently in beta. Your DMARC settings and report collection address are available on your domain's settings page.

Setting Up Your DMARC DNS Record

Add a TXT record to your DNS:

Hostname Type Value
_dmarc.yourdomain.com TXT v=DMARC1; p=none; pct=100; rua=mailto:YOUR_RUA_ADDRESS; aspf=r;

Your unique report address (rua) is shown on your domain settings page. Replace YOUR_RUA_ADDRESS with the address from your settings. For example:

_dmarc.example.com  TXT  "v=DMARC1; p=none; pct=100; rua=mailto:YOUR_RUA_ADDRESS; aspf=r;"

Adding to an Existing DMARC Record

If you already have a DMARC record, add CloudMailin's report address using a comma:

v=DMARC1; p=quarantine; rua=mailto:existing@example.com,mailto:YOUR_RUA_ADDRESS;

Policy Progression

Your DMARC policy tells receiving servers what action to take when messages fail authentication:

Policy Action
p=none Monitor only - failing messages are delivered normally
p=quarantine Failing messages are treated as suspicious (typically marked as spam)
p=reject Failing messages are blocked and not delivered

Recommendation: Start with p=none to monitor without affecting delivery. See our Complete DMARC Guide for guidance on policy progression.

For full DMARC compliance, ensure your SPF record includes CloudMailin's sending servers. If you're sending from a subdomain (e.g., mta.example.com), SPF is automatically configured via CNAME.

For parent domains, add your sending subdomain to your SPF:

v=spf1 include:mta.example.com ~all

This ensures SPF alignment with your From domain for stronger DMARC authentication.

DMARC Reports Dashboard

Beta Feature: CloudMailin automatically collects DMARC reports from all major email providers and displays them in an easy-to-use dashboard. Reports are parsed from XML and categorized by authentication status.

DMARC reports are sent daily by receiving servers. Wait 24-48 hours after adding your DNS record for the first reports to arrive.

Learn More

For a complete guide to DMARC policies, alignment, report interpretation, and best practices, see our Complete DMARC Guide.