chore: migrate SMTP from mx.jeffemmett.com to mail.rmail.online

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

.env.example

@@ -1,5 +1,5 @@
 # SMTP settings (Mailcow)
-SMTP_HOST=mx.jeffemmett.com
+SMTP_HOST=mail.rmail.online
 SMTP_PORT=587
 SMTP_USER=noreply@jefflix.lol
 SMTP_PASS=your-mailbox-password

docker-compose.yml

@@ -2,8 +2,15 @@ services:
   jefflix:
     build: .
     restart: unless-stopped
+    read_only: true
+    tmpfs:
+      - /tmp
+    cap_drop:
+      - ALL
+    security_opt:
+      - no-new-privileges:true
     environment:
-      - SMTP_HOST=${SMTP_HOST:-mx.jeffemmett.com}
+      - SMTP_HOST=${SMTP_HOST:-mail.rmail.online}
       - SMTP_PORT=${SMTP_PORT:-587}
       - SMTP_USER=${SMTP_USER}
       - SMTP_PASS=${SMTP_PASS}