diff --git a/Dockerfile b/Dockerfile
index 46abc83..8e002b9 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -4,7 +4,7 @@ MAINTAINER Larry Price <larry@larry-price.com>
 ENV DEBIAN_FRONTEND noninteractive
 
 RUN /usr/bin/lsb_release -a
-RUN apt-get update && apt-get install git sendmail sendmail-bin supervisor apache2 libjpeg-turbo8-dev fontconfig \
+RUN apt-get update && apt-get install git postgresql sendmail sendmail-bin supervisor apache2 libjpeg-turbo8-dev fontconfig \
                                       libapache2-mod-php5 php5-pgsql php5-curl php5-xmlrpc xfonts-75dpi openssl build-essential \
                                       xorg libssl-dev wget telnet nmap -y --force-yes
 RUN wget http://downloads.sourceforge.net/wkhtmltopdf/wkhtmltox-0.12.2.1_linux-trusty-amd64.deb
diff --git a/README.md b/README.md
index f221a97..0582870 100644
--- a/README.md
+++ b/README.md
@@ -21,3 +21,10 @@ $ docker run -h `hostname -f` -d -p 80:80 --name rosariosis --link rosariodb:ros
 ```
 
 Port 80 will be exposed, so you can visit `localhost` to get started. The default username is `admin` and the default password is `admin`.
+
+## SMTP
+
+RosarioSIS will attempt to send mail via the host's port 25.  In order for this to work you must set the hostname of the resariosis container to that of host (or some other hostname that your can appear on a legal FROM line) and configure the host to accept SMTP from the container.   For postfix this means adding the container IP addresses to /etc/postfix/main.cf as in:
+
+mynetworks = 192.168.0.0/16 172.16.0.0/12 10.0.0.0/8 127.0.0.0/8 [::ffff:127.0.0.0]/104 [::1]/128
+