Step1: expose managesieve, make the webmails use it

core/dovecot/conf/dovecot.conf

@@ -135,10 +135,16 @@ service lmtp {
 service managesieve-login {
   inet_listener sieve {
     port = 4190
+    haproxy = yes
   }
 }
 
+protocol sieve {
+  ssl = no
+}
+
 service managesieve {
+  process_limit = 1024
 }
 
 plugin {

core/nginx/Dockerfile

@@ -17,7 +17,8 @@ ARG VERSION
 LABEL version=$VERSION
 
 RUN set -euxo pipefail \
-  ; apk add --no-cache certbot nginx nginx-mod-mail openssl
+  ; apk add --no-cache certbot nginx nginx-mod-http-brotli nginx-mod-stream nginx-mod-mail openssl \
+  ; rm /etc/nginx/conf.d/stream.conf
 
 COPY conf/ /conf/
 COPY --from=static /static/ /static/
@@ -25,7 +26,7 @@ COPY *.py /
 
 RUN echo $VERSION >/version
 
-EXPOSE 80/tcp 443/tcp 110/tcp 143/tcp 465/tcp 587/tcp 993/tcp 995/tcp 25/tcp 10025/tcp 10143/tcp
+EXPOSE 80/tcp 443/tcp 110/tcp 143/tcp 465/tcp 587/tcp 993/tcp 995/tcp 25/tcp 14190/tcp 10025/tcp 10143/tcp
 HEALTHCHECK --start-period=60s CMD curl -skfLo /dev/null http://localhost/health
 
 VOLUME ["/certs", "/overrides"]

core/nginx/conf/nginx.conf

@@ -1,9 +1,11 @@
 # Basic configuration
 user nginx;
 worker_processes auto;
+pcre_jit on;
 error_log /dev/stderr notice;
 pid /var/run/nginx.pid;
 load_module "modules/ngx_mail_module.so";
+load_module "modules/ngx_stream_module.so";
 
 events {
     worker_connections 1024;
@@ -275,6 +277,25 @@ http {
     include /etc/nginx/conf.d/*.conf;
 }
 
+stream {
+    log_format main '$remote_addr [$time_local] '
+    		'$protocol $status $bytes_sent $bytes_received '
+    		'$session_time "$upstream_addr" '
+    		'"$upstream_bytes_sent" "$upstream_bytes_received" "$upstream_connect_time"';
+    access_log /dev/stdout main;
+
+    # managesieve
+    server {
+      listen 14190;
+      resolver {{ RESOLVER }} valid=30s;
+
+      proxy_connect_timeout 1s;
+      proxy_timeout 1m;
+      proxy_protocol on;
+      proxy_pass {{ IMAP_ADDRESS }}:4190;
+    }
+}
+
 mail {
     server_name {{ HOSTNAMES.split(",")[0] }};
     auth_http http://127.0.0.1:8000/auth/email;

webmails/roundcube/config/config.inc.php

@@ -28,7 +28,7 @@ $config['default_host']  = '{{ FRONT_ADDRESS or "front" }}';
 $config['default_port'] = '10143';
 
 // Sieve script management
-$config['managesieve_host'] = '{{ IMAP_ADDRESS or "imap" }}';
+$config['managesieve_host'] = '{{ FRONT_ADDRESS or "front" }}:14190';
 
 // We access the IMAP and SMTP servers locally with internal names, SSL
 // will obviously fail but this sounds better than allowing insecure login

webmails/snappymail/defaults/default.json

@@ -32,8 +32,8 @@
         "usePhpMail": false
     },
     "Sieve": {
-        "host": "{{ IMAP_ADDRESS }}",
-        "port": 4190,
+        "host": "{{ FRONT_ADDRESS }}",
+        "port": 14190,
         "secure": 0,
         "shortLogin": false,
         "ssl": {