--- title: "Iowa Trucking Email Security — 73.0% lack DMARC | EFROS" description: "Email-security posture of 5,584 active motor carriers in Iowa. 73.0% of domains have no enforced DMARC, 11.3% use p=reject. Free, public, source-cited." canonical: https://efros.com/research/us-trucking-email-security-index/by-state/iowa/ --- - [Home](https://efros.com/) - /[Research](https://efros.com/research/) - /[US Trucking Email Security Index](https://efros.com/research/us-trucking-email-security-index/) - /[By State](https://efros.com/research/us-trucking-email-security-index/by-state/) - /Iowa By State / Iowa # Iowa Trucking Email Security **73.0%** of active carrier domains in Iowa have no enforced DMARC. That leaves freight operators open to email impersonation, payment-redirect fraud, and cargo theft via phishing. Edition: 2026-Q2 State rank: #23 Carriers: 5,584 Domains: 3,611 By [Stefan Efros](https://www.linkedin.com/in/stefanefros-cyberdefense/), CEO & Founder, EFROS Updated · May 19, 2026 No enforced DMARC 73.0% national: 80.1% p=reject 11.3% national: 7.5% Microsoft 365 42.5% national: 38.1% M365 + no DMARC (carriers) 1,147 national: 92,822 MTA-STS 3.8% national: 3.3% DNSSEC 4.8% national: 6.1% Dead domains 172 of 3,611 scanned Total carriers 5,584 172 with dead domain ## Risk bands — Iowa carriers Carrier counts by risk band (composite email-security pain score). Critical = score 70+; Minimal = score <15. | Risk band | Score range | Carriers | Domains | | --- | --- | --- | --- | | Critical | score 70+ | 352 | 268 | | High | score 50–69 | 1,828 | 993 | | Medium | score 30–49 | 2,026 | 1,409 | | Low | score 15–29 | 1,158 | 733 | | Minimal | score ## Iowa vs. national average No enforced DMARC 73.0% vs 80.1% national p=reject adoption 11.3% vs 7.5% national MTA-STS 3.8% vs 3.3% national DNSSEC 4.8% vs 6.1% national ## What the Iowa numbers actually mean **DMARC posture.** Iowa's share of carrier domains with no enforced DMARC sits at **73.0%**, better than the national average by 7.1 points. Iowa carriers adopt the enforced p=reject DMARC policy at a meaningfully higher rate than the national pool. At the protective end of the distribution, 11.3% of Iowa domains are at p=reject, the only DMARC policy that actually instructs receivers to drop spoofed mail. **Microsoft 365 surface.** Microsoft 365 mailflow adoption is heavier than the national distribution. Every M365 tenant already includes the controls needed to enforce DMARC, so the 1,147 M365 carriers in Iowa with DMARC disabled are leaving paid-for protection switched off. That share is **20.5%** of all Iowa carriers — a one-flag-flip remediation set that any regional MSP or in-house IT lead can clear in a single quarter. **Transport encryption.** MTA-STS adoption sits at 3.8%, materially below the threshold a freight payment-redirect attacker would have to clear to be inconvenienced by transport-layer policy. DNSSEC adoption in Iowa runs at **4.8%** (vs 6.1% national), which matters for downstream DKIM and MTA-STS validation but is still a minority signal. **Risk-band shape.** Iowa's critical-band share is 6.3% versus 8.4% nationally, with the pressure shifting into the high band (32.7% of state carriers) where one or two control gaps still leave room for impersonation. The composite pain score blends SPF posture, DMARC enforcement, MTA-STS presence, and DNSSEC, so a carrier clusters in the critical band only when several controls fail together. Remediation that flips DMARC to enforcement plus turns on MTA-STS typically moves a carrier two bands down in one quarter. **What this means for buyers and shippers.** If you are dispatching freight, settling broker payments, or receiving rate confirmations from Iowa-based carriers, the operational exposure is the 73.0%of domains that cannot stop a stranger from sending email in the carrier's name. Payment-redirect and load-redirect fraud rides on exactly that gap. Verifying a counterparty's DMARC posture before a first wire (a 30-second DNS lookup) is the cheapest control in the freight stack. ## Compare Iowa with other states States closest in carrier-count rank to Iowa. Each is scored on the same DNS-derived control set, so the comparison is apples-to-apples. [### Arizona Rank #2279.5% no DMARC · 6,280 carriers](https://efros.com/research/us-trucking-email-security-index/by-state/arizona/) [### Utah Rank #2478.9% no DMARC · 5,271 carriers](https://efros.com/research/us-trucking-email-security-index/by-state/utah/) [### Oregon Rank #2177.5% no DMARC · 5,752 carriers](https://efros.com/research/us-trucking-email-security-index/by-state/oregon/) [### Missouri Rank #2574.5% no DMARC · 6,074 carriers](https://efros.com/research/us-trucking-email-security-index/by-state/missouri/) [### Alabama Rank #2079.6% no DMARC · 5,925 carriers](https://efros.com/research/us-trucking-email-security-index/by-state/alabama/) [← Full US Trucking Email Security Index](https://efros.com/research/us-trucking-email-security-index/) [← All states](https://efros.com/research/us-trucking-email-security-index/by-state/) [Switch to cargo-segment view →](https://efros.com/research/us-trucking-email-security-index/by-cargo/) ## See where your own domain stands The research is free and self-serve. Run the same public checks on your own domain in about a minute — SPF, DKIM, DMARC, MTA-STS, DNSSEC, and more — and get a scored report by email. No agents, no credentials. [Scan your domain free →](https://efros.com/tools/security-scan/) [Email security for fleets](https://efros.com/industries/trucking-company-msp/) [Talk to EFROS](https://efros.com/contact/?source=trucking-email-research) Data as of 2026-05-20from public DNS measurements. Statistics are domain-weighted unless noted. State scope is the carrier's FMCSA-registered state. Methodology: [read the full index](https://efros.com/research/us-trucking-email-security-index/).