diff --git a/doc/debian_ubuntu.sh b/doc/debian_ubuntu.sh
index 11533285..1eecd18c 100644
--- a/doc/debian_ubuntu.sh
+++ b/doc/debian_ubuntu.sh
@@ -3,7 +3,7 @@
 sudo apt-get update
 sudo apt-get upgrade
 
-sudo apt-get install -y git git-core wget curl gcc checkinstall libxml2-dev libxslt-dev sqlite3 libsqlite3-dev libcurl4-openssl-dev libreadline-gplv2-dev libc6-dev libssl-dev libmysql++-dev make build-essential zlib1g-dev libicu-dev redis-server openssh-server python-dev python-pip libyaml-dev
+sudo apt-get install -y git git-core wget curl gcc checkinstall libxml2-dev libxslt-dev sqlite3 libsqlite3-dev libcurl4-openssl-dev libreadline-gplv2-dev libc6-dev libssl-dev libmysql++-dev make build-essential zlib1g-dev libicu-dev redis-server openssh-server python-dev python-pip libyaml-dev sendmail
 
 wget http://ftp.ruby-lang.org/pub/ruby/1.9/ruby-1.9.3-p194.tar.gz
 tar xfvz ruby-1.9.3-p194.tar.gz