RHEL 7 Postfix Queue Stuck By SELinux Policy

📖 ~1 min read

Table of contents

1. Symptom & Impact
2. Environment & Reproduction
3. Root Cause Analysis
4. Quick Triage
5. Step-by-Step Diagnosis
6. Solution – Primary Fix
7. Solution – Alternative Approaches
8. Verification & Acceptance Criteria
9. Rollback Plan
10. Prevention & Hardening
11. Related Errors & Cross-Refs
12. References & Further Reading

Symptom & Impact

Postfix accepts messages but delivery queue grows and outbound mail stalls.

Environment & Reproduction

RHEL 7 mail relay with SELinux enforcing shows repeated deferred deliveries and timeout behavior.

Root Cause Analysis

SELinux denies Postfix network or file access required by relay or content filter integration.

Quick Triage

Inspect mail log and journalctl, then correlate with AVC entries in audit log for exact denial context.

Step-by-Step Diagnosis

Run sealert or audit2why, validate postfix config paths, and check boolean states impacting mail flow.

Solution – Primary Fix

Set appropriate SELinux booleans, correct context labels, restart postfix service, and flush queue.

Solution – Alternative Approaches

Separate filtering components to dedicated hosts with clearer policy boundaries and minimal context overlap.

Verification & Acceptance Criteria

Queue drains normally, remote deliveries succeed, and no new AVC denials appear.

Rollback Plan

Undo boolean changes and revert configuration if policy update introduces unintended mail exposure.

Prevention & Hardening

Review SELinux impacts during mail stack changes and validate relay tests in staging.

Related Errors & Cross-Refs

Related to DNS/firewalld issues that also cause deferred outbound SMTP transactions.

Related tutorial: View the step-by-step tutorial for rhel-7.

View all rhel-7 tutorials on the Tutorials Hub →

Browse all common problems & solutions on the Tutorials Hub.

References & Further Reading

Use RHEL SELinux mail service documentation and Postfix operational troubleshooting guides.