Oracle Linux 10 – Common Problem 043 – Diagnosis and Fix

📖 ~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

Mail relay attempts fail due to SELinux denials in postfix context.

Environment & Reproduction

Queue grows and logs show permission denied despite correct credentials.

Root Cause Analysis

Use ausearch -m AVC and journalctl -u postfix to correlate failures.

Quick Triage

Missing SELinux boolean or mislabeled certificate/key files.

Step-by-Step Diagnosis

Enable required boolean and restorecon on postfix TLS assets.

Solution – Primary Fix

Send test mail and verify queue flush without AVC entries.

Solution – Alternative Approaches

Include SELinux context checks in mail server hardening.

Verification & Acceptance Criteria

Revert recent policy customizations if mail flow regresses.

Rollback Plan

Apply postfix and SELinux settings using repeatable role.

Prevention & Hardening

setsebool -P; restorecon -Rv /etc/postfix; postqueue -p

Related Errors & Cross-Refs

Share AVC logs and postfix main.cf excerpts.

Related tutorial: View the step-by-step tutorial for oracle-linux-10.

View all oracle-linux-10 tutorials on the Tutorials Hub →

Browse all common problems & solutions on the Tutorials Hub.

References & Further Reading

Temporary permissive mode should be used only for diagnostics.