diff --git a/Dockerfile b/Dockerfile
index d7dd15a9..bf4ab16d 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -7,7 +7,7 @@ RUN apt-get -y upgrade
 RUN DEBIAN_FRONTEND=noninteractive apt-get -y install vim postfix sasl2-bin courier-imap courier-imap-ssl \
     courier-pop courier-pop-ssl courier-authdaemon supervisor gamin amavisd-new spamassassin clamav clamav-daemon libnet-dns-perl libmail-spf-perl \
     pyzor razor arj bzip2 cabextract cpio file gzip nomarch p7zip pax unzip zip zoo rsyslog mailutils netcat \
-    opendkim opendkim-tools opendmarc
+    opendkim opendkim-tools opendmarc curl
 RUN apt-get autoclean && rm -rf /var/lib/apt/lists/*
 
 # Configures Saslauthd
@@ -44,7 +44,6 @@ ADD postfix/default-opendkim /etc/default/opendkim
 ADD postfix/opendmarc.conf /etc/opendmarc.conf
 ADD postfix/default-opendmarc /etc/default/opendmarc
 
-
 # Configures Postfix
 ADD postfix/main.cf /etc/postfix/main.cf
 ADD postfix/master.cf /etc/postfix/master.cf
@@ -52,6 +51,10 @@ ADD postfix/sasl/smtpd.conf /etc/postfix/sasl/smtpd.conf
 ADD bin/generate-ssl-certificate /usr/local/bin/generate-ssl-certificate
 RUN chmod +x /usr/local/bin/generate-ssl-certificate
 
+# Get LetsEncrypt signed certificate
+RUN curl https://letsencrypt.org/certs/lets-encrypt-x1-cross-signed.pem > /etc/ssl/certs/lets-encrypt-x1-cross-signed.pem
+RUN curl https://letsencrypt.org/certs/lets-encrypt-x2-cross-signed.pem > /etc/ssl/certs/lets-encrypt-x2-cross-signed.pem
+
 # Start-mailserver script
 ADD start-mailserver.sh /usr/local/bin/start-mailserver.sh
 RUN chmod +x /usr/local/bin/start-mailserver.sh
diff --git a/SSL.md b/SSL.md
index e8dd801f..c43b5361 100644
--- a/SSL.md
+++ b/SSL.md
@@ -48,3 +48,13 @@ To use the certificate:
 
 * add an `DMS_SSL=self-signed` to your container environment variables
 * if a matching certificate (files listed above) is found in `postfix/ssl`, it will be automatically setup in postfix and courier-imap-ssl. You just have to place them in `postfix/ssl` folder.
+
+### Testing certificate
+
+From your host:
+
+    docker exec mail openssl s_client -connect 0.0.0.0:587 -starttls smtp -CApath /etc/ssl/certs/
+
+And you should see the certificate chain, the server certificate and:
+
+    Verify return code: 0 (ok)
\ No newline at end of file
diff --git a/test/test.sh b/test/test.sh
index 49a2de27..a6cc6efa 100644
--- a/test/test.sh
+++ b/test/test.sh
@@ -78,5 +78,12 @@ assert "docker exec mail cat /etc/opendmarc.conf | grep ^TrustedAuthservID | wc
 # Testing hostname config
 assert "docker exec mail cat /etc/mailname" "my-domain.com"
 
+# Testing presence of LetsEncrypt signed certs
+assert_raises "docker exec mail grep 'BEGIN CERTIFICATE' /etc/ssl/certs/lets-encrypt-x1-cross-signed.pem" "0"
+assert_raises "docker exec mail grep 'BEGIN CERTIFICATE' /etc/ssl/certs/lets-encrypt-x2-cross-signed.pem" "0"
+
+# Testing generated ssl certs
+assert_raises "docker exec mail openssl s_client -connect 0.0.0.0:587 -starttls smtp -CApath /etc/ssl/certs/ | grep 'Verify return code: 0 (ok)'" "0"
+
 # Ending tests
 assert_end