diff --git a/README.md b/README.md
index df506a4..e16a2c2 100644
--- a/README.md
+++ b/README.md
@@ -4,6 +4,8 @@ Description
 Installs and configures postfix for client or outbound relayhost, or
 to do SASL authentication.
 
+On RHEL-family systems, sendmail will be replaced with postfix.
+
 Requirements
 ============
 
@@ -11,6 +13,8 @@ Requirements
 
 * Ubuntu 10.04+
 * Debian 6.0+
+* RHEL/CentOS/Scientific 5.7+, 6.2+
+* Amazon Linux (as of 4/9/2012)
 
 Attributes
 ==========
diff --git a/metadata.rb b/metadata.rb
index a9eb751..2b449c4 100644
--- a/metadata.rb
+++ b/metadata.rb
@@ -6,7 +6,7 @@ version           "0.8.4"
 recipe            "postfix", "Installs and configures postfix"
 recipe            "postfix::sasl_auth", "Set up postfix to auth to a server with sasl"
 
-%w{ubuntu debian}.each do |os|
+%w{ubuntu debian redhat centos}.each do |os|
   supports os
 end
 
diff --git a/recipes/default.rb b/recipes/default.rb
index 5c97fe5..ef00f91 100644
--- a/recipes/default.rb
+++ b/recipes/default.rb
@@ -23,9 +23,23 @@ package "postfix" do
 end
 
 service "postfix" do
+  supports :status => true, :restart => true, :reload => true
   action :enable
 end
 
+case node[:platform]
+when "redhat", "centos", "amazon", "scientific"
+  service "sendmail" do
+    action :nothing
+  end
+  execute "switch_mailer_to_postfix" do
+    command "/usr/sbin/alternatives --set mta /usr/sbin/sendmail.postfix"
+    notifies :stop, resources(:service => "sendmail")
+    notifies :start, resources(:service => "postfix")
+    not_if "/usr/bin/test /etc/alternatives/mta -ef /usr/sbin/sendmail.postfix"
+  end
+end
+
 %w{main master}.each do |cfg|
   template "/etc/postfix/#{cfg}.cf" do
     source "#{cfg}.cf.erb"
@@ -35,3 +49,7 @@ end
     notifies :restart, resources(:service => "postfix")
   end
 end
+
+service "postfix" do
+  action :start
+end