diff --git a/config.toml b/config.toml
index 7183fb4..8e67721 100755
--- a/config.toml
+++ b/config.toml
@@ -591,7 +591,7 @@ key = ["rcpt-domain"]
 concurrency = 5
 
 [resolver]
-type = "system"
+type = "custom"
 #preserve-intermediates = true
 concurrency = 2
 timeout = "5s"
@@ -609,6 +609,11 @@ ptr = 1024
 tlsa = 1024
 mta-sts = 1024
 
+[[resolver.nameservers]]
+ip = "10.222.222.1"
+port = 53
+protocol = "udp"
+
 [report]
 path = "/opt/stalwart-mail/reports"
 hash = 64
diff --git a/docker/Dockerfile b/docker/Dockerfile
index b14b035..22c1c9e 100644
--- a/docker/Dockerfile
+++ b/docker/Dockerfile
@@ -7,6 +7,16 @@ ARG VERSION="0.4.2"
 ADD https://github.com/stalwartlabs/mail-server/archive/refs/tags/v$VERSION.tar.gz /tmp/v$VERSION.tar.gz
 RUN tar --strip-components=1 -C /source -xzf /tmp/v$VERSION.tar.gz
 
+RUN apt update && apt install -y patch
+
+# Enhancement: Custom resolver nameservers
+ADD https://patch-diff.githubusercontent.com/raw/stalwartlabs/mail-server/pull/141.patch /tmp/141.patch
+RUN patch -p1 < /tmp/141.patch
+
+# Fix: Return an error to client if STARTTLS is not available
+ADD https://patch-diff.githubusercontent.com/raw/stalwartlabs/mail-server/pull/135.patch /tmp/135.patch
+RUN patch -p1 < /tmp/135.patch
+
 FROM --platform=$BUILDPLATFORM docker.io/lukemathwalker/cargo-chef:latest-rust-slim-bookworm AS chef
 WORKDIR /build