SenderLock

Guides · Updated 2026-10-11

DMARC for MSPs: managing many client domains

For MSPs, DMARC is a recurring service with clear value: clients' domains get spoofed in invoice fraud, and Gmail, Yahoo and Microsoft now require authentication from bulk senders.

A repeatable playbook

  1. Baseline every client: grade all domains (including parked ones) for DMARC, SPF, DKIM and MTA-STS.
  2. Publish p=none + reporting everywhere in one change window.
  3. Fix senders per client: Microsoft 365 or Google Workspace DKIM first, then marketing, CRM and billing platforms.
  4. Lock down parked domains immediately (guide).
  5. Enforce client by client, with alerts for new failing sources.

Packaging it

Bundle it as monthly per-domain monitoring. SenderLock's planned MSP pricing is a flat $3 to $4 per client domain with no minimums and white-label reports. See MSP pricing.

Check your domain now. Our free checker grades DMARC, SPF, DKIM, MX, BIMI and MTA-STS in seconds.

Sources

This guide is general information, not legal or professional advice. Provider screens change; always confirm the exact values shown in your own account.