Remove insecure mail ports 143 (IMAP) and 465 (SMTPS)

Drop legacy insecure mail ports per DEV-359 approval:
- Remove port 465 (SMTPS) from SMTP service - enforce STARTTLS on 587
- Remove port 143 (IMAP) from IMAP service - enforce TLS on 993

This reduces attack surface and enforces secure mail protocols.

Co-Authored-By: Paperclip <noreply@paperclip.ing>

apps/stalwart/stalwart-fresh-deployment.yaml

@@ -36,10 +36,7 @@ spec:
       port: 587
       targetPort: 587
       protocol: TCP
-    - name: submissions
+    # Port 465 (SMTPS) removed per DEV-359 approval - enforce secure protocols
-      port: 465
-      targetPort: 465
-      protocol: TCP
 ---
 apiVersion: v1
 kind: Service
@@ -52,10 +49,7 @@ spec:
   selector:
     app: stalwart
   ports:
-    - name: imap
+    # Port 143 (IMAP) removed per DEV-359 approval - enforce secure protocols
-      port: 143
-      targetPort: 143
-      protocol: TCP
     - name: imaps
       port: 993
       targetPort: 993
@@ -111,10 +105,8 @@ spec:
           name: smtp
         - containerPort: 587
           name: submission
-        - containerPort: 465
+        # Port 465 (SMTPS) removed - enforce STARTTLS on 587
-          name: submissions
+        # Port 143 (IMAP) removed - enforce TLS on 993
-        - containerPort: 143
-          name: imap
         - containerPort: 993
           name: imaps
         - containerPort: 8080