Tennessee K-12 Email Security Intelligence:
DNS Authentication Profiling of 148 School District LEAs

Lokentra Research Team
Lokentra U.S. Email Security Index (ESI) — State Intelligence Series
April 22, 2026
research@monitorworkspace.com • monitorworkspace.com/scorecard

Abstract

We present DNS email security profiling for 148 K-12 LEAs in Tennessee, of which 136 have active domains (91.9% coverage). Domains were scored on the Lokentra 100-point Email Security Index (ESI) rubric (SPF 30 pts + DKIM 30 pts + DMARC 40 pts). Tennessee K-12 districts achieve an average ESI score of 45.1/100, with 28.7% earning Grade A or B (strong posture) and 36.8% receiving Grade F (minimal authentication). Only 40.4% have any DMARC record, and just 25.7% have DMARC at an enforcement level (quarantine or reject) — leaving 59.6% of districts fully vulnerable to email domain spoofing. This report provides entity-level data for all 136 scored domains including provider classification, authentication status, and ESI score, sourced from NCES CCD 2024-2025 and live DNS resolution conducted April 22, 2026.

Keywords: Tennessee, K-12 email security, DMARC, SPF, school district cybersecurity, DNS authentication, Google Workspace, education technology

1. Dataset Overview

Table 1. Tennessee K-12 Dataset Summary
MetricValue
Total K-12 LEAs in state148
Regular school districts140
Charter LEAs1
Other LEA types (state-operated, regional, etc.)7
LEAs with active internet domain136 (91.9%)
Domains DNS-profiled136
Data freshness (NCES CCD)2024-2025 school year
DNS scan dateApril 22, 2026

2. The Human Impact: Populations at Risk

To estimate human exposure, NCES national averages are applied to CCD 2024-2025 operational school counts: 381 students per school, 51 staff per school, and 2 parents or guardians per student. Tennessee K-12 districts collectively operate approximately 1,910 schools.

Table 2. Estimated Population Exposure from K-12 Email Security Gaps — Tennessee
PopulationTotal in DatasetAt Risk (No DMARC, 59.6%)Critically Exposed (Grade F, 36.8%)
Students727,710433,715267,797
Parents and guardians1,455,420867,430535,594
Staff and educators97,41058,05635,846
Total people2,280,5401,359,201839,238

Estimates based on NCES national averages. Individual district enrollment data can be linked via NCES LEAID for precise counts.

3. Authentication Findings

3.1 Protocol Adoption

Table 3. Email Authentication Protocol Adoption — Tennessee K-12
ProtocolTennesseeNational K-12 (ESI)vs. National
SPF (any configuration)72.8%79.7%-6.9pp
DKIM (key published)50.7%59.6%-8.9pp
DMARC (any policy)40.4%55.5%-15.1pp
DMARC at enforcement (quarantine/reject)25.7%~21.0%+4.7pp
DMARC at reject (full enforcement)9.6%~12.2%-2.6pp
No MX records (not receiving email)21.3%~10.0%+11.3pp

3.2 ESI Grade Distribution

Table 4. ESI Score Grade Distribution — Tennessee K-12
GradeScoreDistrictsShareInterpretation
A90–1002115.4%Full enforcement
B70–891813.2%Strong posture
C50–692921.3%Partial protection
D30–491813.2%Weak configuration
F0–295036.8%Minimal/no authentication
Average score45.1 / 100

3.3 Email Provider Distribution

Table 5. Email Provider Distribution — Tennessee K-12 (top providers)
ProviderDistrictsShare
Google Workspace5842.6%
Microsoft 3653324.3%
Barracuda53.7%
Proofpoint32.2%
GoDaddy21.5%

4. District-Level Data

4.1 Top Performing Districts (Best ESI Scores)

Table 6. Top 15 Tennessee K-12 Districts by ESI Score
DistrictDomainCountyProviderSPFDKIMDMARC PolicyScoreGrade
Collierville colliervilleschools.org Shelby County Microsoft 365 reject 100 A
Arlington acsk-12.org Shelby County Microsoft 365 reject 100 A
Montgomery County cmcss.net Montgomery County Proofpoint reject 100 A
Polk County polk-schools.com Polk County Google Workspace reject 100 A
Tennessee Public Charter School Commission tn.gov Davidson County Proofpoint reject 95 A
Lakeland lakelandk12.org Shelby County Google Workspace reject 95 A
DeKalb County dekalbschools.net DeKalb County Google Workspace reject 95 A
Kingsport k12k.com Sullivan County Barracuda reject 95 A
Lebanon lssd.org Wilson County Google Workspace reject 95 A
Pickett County pickettk12.net Pickett County Google Workspace reject 95 A
Sevier County sevier.org Sevier County Google Workspace reject 95 A
West Carroll Sp Dist wcssd.org Carroll County Microsoft 365 reject 95 A
Greeneville gcschools.net Greene County Barracuda reject 93 A
Bartlett bartlettschools.org Shelby County Microsoft 365 quarantine 90 A
Lewis County lewisk12.org Lewis County Microsoft 365 quarantine 90 A

4.2 Districts Most in Need of Improvement (Lowest ESI Scores)

Table 7. Bottom 15 Tennessee K-12 Districts by ESI Score
DistrictDomainCountyProviderSPFDKIMDMARC PolicyScoreGrade
Bedford County bedfordk12tn.com Bedford County 0 F
Bledsoe County bledsoe.k12.tn.us Bledsoe County 0 F
Campbell County campbell.k12.tn.us Campbell County 0 F
Bradley County bcvs.bradleyschools.org Bradley County 0 F
Claiborne County claibornecountyschools.com Claiborne County Google Workspace 0 F
Carter County carterk12.org Carter County 0 F
Crockett County ccetc.org Crockett County 0 F
Dickson County dicksoncountyschools.org Dickson County 0 F
Fentress County fentress.k12tn.net Fentress County 0 F
Giles County giles-lea.giles.k12.tn.us Giles County 0 F
Grundy County grundycoschools.com Grundy County 0 F
Hancock County hancockcountyschools.com Hancock County Google Workspace 0 F
Hardin County hardin.k12.tn.us Hardin County 0 F
Haywood County haywoodschools.com Haywood County GoDaddy 0 F
Houston County houston.k12.tn.us Houston County 0 F

4.3 County-Level Summary (Top 10 Counties by District Count)

Table 8. Tennessee County Distribution
CountyDistrictsWebsite Coverage
Shelby County7100.0%
Carroll County666.7%
Gibson County580.0%
Davidson County4100.0%
Coffee County4100.0%
Crockett County366.7%
Blount County3100.0%
Anderson County3100.0%
McMinn County3100.0%
Sullivan County3100.0%

5. Policy Implications

These findings identify specific, actionable gaps in Tennessee's K-12 email security posture. The 59.6% DMARC gap represents districts that can be impersonated by any sender, enabling phishing campaigns targeting parents, students, and educators with no authentication failure. Key observations:

6. Data Availability

The full Tennessee K-12 dataset — 148 entities with NCES CCD enrichment (phone, address, grade span, school count, LEAID) and DNS authentication profiles — is available as part of the Lokentra ESI State Pack.

Table 9. Licensing Tiers
TierScopeSuggested Use
State Pack: TennesseeAll 148 K-12 LEAs, full DNS profile + CCD enrichmentRegional studies, state policy, outreach
K-12 NationalAll 50 states, 20,021+ K-12 LEAsNational K-12 cybersecurity research
Full Registry801,359+ entities across all sectorsComprehensive multi-sector research
API + UpdatesQuarterly re-scan, REST APILongitudinal studies, live dashboards

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Citation: Lokentra Research Team (2026). Tennessee K-12 Email Security Intelligence: DNS Authentication Profiling of 148 School District LEAs. Lokentra U.S. Email Security Index (ESI) — State Intelligence Series. https://lokentra-site.web.app/research/states/tn-k12-paper.html

Data sources: NCES Common Core of Data (CCD) 2024-2025; DNS records resolved via Google Public DNS (8.8.8.8) and Cloudflare (1.1.1.1). All entity data derived from publicly accessible government registries.

National baseline figures from Lokentra U.S. Education Sector Email Security Intelligence Dataset (March 2026). See education-dataset-paper.html for full methodology.