Deliverability used to be a separate concern from SEO. Then Google and Yahoo tightened. Now every marketing campaign — cold outreach, transactional, newsletter, drip — depends on whether your client’s DMARC is p=reject and aligned, whether their SPF hasn’t blown the 10-DNS-lookup budget, and whether their DKIM keys are actually signing.
For agencies, this is a discovery problem more than a technical one. Your client onboards. They tell you their email works. You launch a campaign. Half the mail’s in spam. The client thinks it’s the content. It’s not — it’s the DMARC record you never checked.
What Changed (2024-2026)
Google + Yahoo bulk-sender rules — effective February 2024, tightened to permanent rejection in November 2025. Any sender pushing >5K/day to Gmail or Yahoo without DMARC alignment gets rejected. That’s every drip campaign, every launch email, every promotional blast.
PCI DSS 4.0.1 Req 5.4.1 — effective March 2025. If your client sells online, this touches them. DMARC / SPF / DKIM / MTA-STS are named example implementations of the mandated automated anti-phishing controls.
NIS2 Implementing Regulation (EU) 2024/2690 — SPF + DKIM + DMARC + MTA-STS + DANE required for in-scope entities. Fines up to €10M or 2% global revenue.
Any of your clients international? Serving EU customers? PCI-scoped? These aren’t hypothetical.
The Deliverability Fire Drill
Your client launches a big campaign. The metrics look wrong.
Without DomainScan:
- Log into their email provider dashboard (Mailchimp / HubSpot / SendGrid)
- Check bounce rates
- Ask which DNS provider they use
- Log into their DNS
- Look up their SPF record
- Count the DNS lookups
- Realize it’s over 10
- Check DMARC
- Not published
- Six hours of debugging, meanwhile the campaign is torched
With DomainScan:
- Enter the client’s domain
- Full email auth report in seconds
- Every issue flagged with a paste-ready fix
- 15 minutes to remediation
Onboarding Every New Client
Standard first-week deliverable when you onboard a new client:
- Run a live scan on their root domain plus every subdomain used for mail
- Export the trust score + email auth report
- Deliver as a “current state” audit — this becomes the baseline for your engagement
- Set up continuous monitoring so any breakage surfaces before their marketing team notices
Half your clients will discover deliverability issues they didn’t know they had. The audit itself becomes a case for scope expansion.
Bundling for Agency Margins
Two common patterns:
Bundle into retainer. Add “email deliverability + DMARC monitoring” as a line item on every retainer. $200-500/mo per client, positioned against the price of a lost campaign.
Resell as productized service. “DMARC-as-a-Service” line — flat $99-299/mo per client. Handle setup, deploy, monitor, escalate only when something breaks. Recurring revenue with limited variable delivery cost.
Where DomainScan Fits vs Alternatives
- Dedicated DMARC tools (dmarcian, EasyDMARC, Valimail) — deeper DMARC-specific features, higher per-client cost, DMARC-only scope. See our dmarcian comparison and Valimail comparison.
- General-purpose monitoring (Datadog, New Relic) — no DMARC or DNS awareness, too generic for this use case.
- DomainScan — DMARC + DNS + SSL + blacklist + subdomain security in one platform at agency-friendly pricing.
Related
Read what DMARC is, how to set up DMARC for Google Workspace, and the dmarcian comparison.