From Debian package 0.2.20100524-5

  * Added in_unconfined_r() interface and made postfix user domains use it
    so they can be in the role unconfined_r.  Ugly but no better solution at
    this time
    Closes: #592038 #599053

The addition of the in_unconfined_r interface is in 596_in_unconfined_r

Index: policy/modules/services/postfix.if
===================================================================
--- policy/modules/services/postfix.if.orig
+++ policy/modules/services/postfix.if
@@ -163,6 +163,7 @@
 	allow postfix_$1_t self:capability dac_override;
 
 	domtrans_pattern(postfix_user_domtrans, postfix_$1_exec_t, postfix_$1_t)
+	in_unconfined_r(postfix_$1_t)
 
 	domain_use_interactive_fds(postfix_$1_t)
 ')