Skip to main content
Encrypted Email Transport

Enforce TLS Encryption for All Email

Implement MTA-STS to enforce TLS encryption for inbound email and TLS-RPT for monitoring. Includes free MTA-STS policy file hosting on our infrastructure.

Free Policy Hosting
99.9% Uptime SLA

MTA-STS Status

acme-corp.com

Enforcing
POLICY CONFIGURATION
Mode
enforce
Max Age
604800s
MX Hosts
2 configured
Policy File
Hosted
TLS VERSION DISTRIBUTION (7 DAYS)
TLS 1.3(Preferred)
78%
TLS 1.2(Supported)
21%
TLS 1.1(Deprecated)
1%
12.4K
Successful
23
Warnings
0
Failures
100% TLS
Free Hosting
100%
TLS Enforcement
Free
File Hosting
Real-time
Failure Alerts
99.9%
Uptime SLA
What is MTA-STS?

SMTP Mail Transfer Agent Strict Transport Security

MTA-STS is an email security standard that enables domain owners to declare their mail servers support TLS encryption and instructs sending servers to refuse delivery if a secure connection cannot be established. It prevents man-in-the-middle attacks and encryption downgrade attacks.

Without MTA-STS

  • Email can be intercepted in transit
  • Attackers can force unencrypted delivery
  • No visibility into TLS failures
  • Man-in-the-middle attacks possible
  • Compliance requirements not met

With MTA-STS

  • All email encrypted with TLS 1.2+
  • Downgrade attacks prevented
  • Real-time TLS failure reports
  • MITM attacks blocked
  • Meet HIPAA, PCI, SOC2 requirements

MTA-STS Policy Modes

Progress safely from monitoring to enforcement

mode: none

Discovery

No MTA-STS policy - email delivered without TLS enforcement

Not Protected
mode: testing

Testing Mode

Collect TLS reports without enforcing encryption requirements

Monitoring
Recommended
mode: enforce

Enforce Mode

Reject email from servers that cannot establish TLS

Protected
Progression path:
nonetestingenforce

MTA-STS Implementation Services

End-to-end TLS enforcement with free policy hosting

MTA-STS Policy

Define and publish your email encryption requirements

  • Policy file generation
  • DNS record setup
  • Mode configuration
  • Version management

Free File Hosting

Host your MTA-STS policy file on our global infrastructure

  • HTTPS delivery
  • Global CDN
  • 99.9% uptime SLA
  • No bandwidth limits

TLS-RPT Monitoring

Receive and analyze TLS failure reports from sending servers

  • Report aggregation
  • Failure analysis
  • Trend visualization
  • Root cause identification

Certificate Management

Ensure valid TLS certificates for policy compliance

  • Certificate validation
  • Expiry monitoring
  • Renewal alerts
  • Chain verification

Policy Progression

Safely transition from testing to enforcement mode

  • Testing mode
  • Enforce mode
  • Gradual rollout
  • Rollback support

Failure Alerting

Real-time notifications when TLS connections fail

  • Email alerts
  • Slack integration
  • PagerDuty support
  • Custom thresholds
TLS Reporting (TLS-RPT)

Visibility into TLS Connection Failures

TLS-RPT is a companion standard to MTA-STS that provides feedback when sending servers encounter TLS issues. Get detailed reports about certificate problems, policy failures, and connection errors.

  • Daily aggregate reports from sending servers
  • Certificate validation failures
  • Policy fetch errors
  • Connection negotiation issues
SAMPLE TLS-RPT SUMMARY
Successful TLS
12,847
Certificate Issues
23
Policy Failures
0

Implementation Timeline

From audit to enforcement in weeks, not months

1
1 day

Audit

Assess current TLS configuration and certificate status

  • TLS version check
  • Certificate validation
  • Mail server inventory
2
1-2 days

Configure

Create MTA-STS policy and TLS-RPT DNS records

  • Policy file creation
  • DNS record setup
  • CDN hosting
3
1-2 weeks

Test

Run in testing mode and monitor TLS reports

  • Report collection
  • Failure analysis
  • Issue remediation
4
1 day

Enforce

Switch to enforce mode after successful testing

  • Policy update
  • Verification testing
  • Documentation
5
Ongoing

Monitor

Continuous monitoring and certificate management

  • Report analysis
  • Alert management
  • Certificate renewals

Technology Partners

Industry-leading tools for MTA-STS implementation

Postfix
Let's Encrypt
Cloudflare
Google Workspace
Microsoft 365
Hardenize

Ready to Enforce Email Encryption?

Implement MTA-STS with free policy hosting. Protect your email with mandatory TLS encryption.

Get Free Assessment