Send processed emails to opensmtpd

outbox/Dockerfile

@@ -1,5 +1,9 @@
 FROM node:20-alpine
 WORKDIR /app
 COPY . /app/
+COPY smtpd.conf /etc/smtpd/smtpd.conf
+RUN apk upgrade -U; apk add --no-cache opensmtpd
 RUN npm i --omit=dev
+COPY --chmod=500 entrypoint.sh /entrypoint
+ENTRYPOINT ["/entrypoint"]
 CMD ["src/server.js"]

outbox/entrypoint.sh

@@ -0,0 +1,18 @@
+#!/bin/sh
+
+SPOOL=" /var/spool/smtpd"
+
+chmod 711  "$SPOOL"
+
+chmod 770  "$SPOOL/offline"
+chown 0:102  "$SPOOL/offline"
+
+chmod 700  "$SPOOL/purge"
+chown 101:0  "$SPOOL/purge"
+
+chmod 700  "$SPOOL/queue"
+chown 101:0  "$SPOOL/queue"
+
+smtpd -d -v -P mda &
+
+node "$*"

outbox/smtpd.conf

@@ -0,0 +1,3 @@
+listen on lo
+action "relay" relay
+match from local for any action "relay"

outbox/src/handlers/data.js

@@ -3,6 +3,9 @@ import redis from '../services/redis.js';
 import { Response } from '@carlgo11/smtp-server';
 import signMessage from '../services/dkim.js';
 import fs from 'fs/promises';
+import { promisify } from 'util';
+import { execFile } from 'child_process';
+const execFileAsync = promisify(execFile);
 
 export default async function handleData(message, session) {
   const from = session.mailFrom;
@@ -51,6 +54,8 @@ export default async function handleData(message, session) {
   }
 
   await fs.writeFile(`/tmp/${email.id}.eml`, email.full_email());
+
+  await execFileAsync(`cat /tmp/${email.id} | sendmail -t -v -f ${from}`);
 }
 
 /**

outbox/src/server.js

@@ -9,11 +9,11 @@ const server = Server({
     key: fs.readFileSync(process.env.OUTBOX_TLS_KEY_PATH),
     cert: fs.readFileSync(process.env.OUTBOX_TLS_CERT_PATH),
     handshakeTimeout: 5000,
-    minVersion: 'TLSv1.3',
-    maxVersion: 'TLSv1.3',
-    ALPNProtocols: ['h2'],
+    minVersion: process.env.OUTBOX_TLS_MIN_VERSION || process.env.TLS_MIN_VERSION,
+    maxVersion: process.env.OUTBOX_TLS_MAX_VERSION || process.env.TLS_MAX_VERSION,
+    requestOCSP: true,
   },
-  logLevel: 'DEBUG',
+  logLevel: process.env.LOG_LEVEL || 'INFO',
   extensions: ['ENHANCEDSTATUSCODES', 'PIPELINING', 'AUTH PLAIN', '8BITMIME'],
   onMAILFROM: handleMail,
   onDATA: handleData,