postfix: squeeze fix - mailx now has several alternatives.

manifests/classes/postfix.pp

@@ -42,10 +42,18 @@ class postfix {
   }
 
 
-  package { ["postfix", "mailx"]:
+  package { "postfix":
     ensure => installed
   }
 
+  package { "mailx":
+    ensure => installed,
+    name   => $lsbdistcodename ? {
+      "squeeze" => "bsd-mailx",
+      default   => "mailx",
+    },
+  }
+
   service { "postfix":
     ensure  => running,
     require => Package["postfix"],