deploy: Add mailpit to test *sent* emails

deploy/testing/docker-compose.yml

@@ -29,6 +29,7 @@ services:
       - DB_NAME=system3
       - DB_USER=system3
       - DB_PASSWORD=system3
+      - MAIL_DOMAIN=mail:1025
     volumes:
       - ../../core:/code
       - ../testdata.py:/code/testdata.py
@@ -37,6 +38,7 @@ services:
     depends_on:
       - db
       - redis
+      - mail
 
   frontend:
     build:
@@ -52,5 +54,19 @@ services:
     depends_on:
       - core
 
+  mail:
+    image: docker.io/axllent/mailpit
+    volumes:
+      - mailpit_data:/data
+    ports:
+      - 8025:8025
+      - 1025:1025
+    environment:
+      MP_MAX_MESSAGES: 5000
+      MP_DATABASE: /data/mailpit.db
+      MP_SMTP_AUTH_ACCEPT_ANY: 1
+      MP_SMTP_AUTH_ALLOW_INSECURE: 1
+
 volumes:
-  mariadb_data:
+  mariadb_data:
+  mailpit_data: