Stalwart was blocking the HTTP port (8080) from Traefik's internal IP
(10.244.2.227), causing 502 errors when accessing mail.basicstack.de.
Changes:
- Added complete Stalwart TOML configuration (stalwart-config.yaml)
- Configured HTTP listener security to allow internal pod network (10.244.0.0/16)
- Updated StatefulSet to use the new configuration file
- This allows Traefik ingress to reach the Stalwart web UI backend
The fix is non-destructive:
- PVC data is preserved
- Rolling update will restart the pod with new config
- Only security setting is changed (adding allowed IPs)
Fixes: DEV-422
Co-Authored-By: Paperclip <noreply@paperclip.ing>