From Debian package 0.2.20100524-3

  * Label /etc/network/if-(up|down).d/postfix as initrc_exec_t so that udev
    can reload Postfix and push the queue.

Index: policy/modules/services/postfix.fc
===================================================================
--- policy/modules/services/postfix.fc.orig
+++ policy/modules/services/postfix.fc
@@ -29,6 +29,8 @@
 /usr/lib(64)?/postfix/bounce	-- gen_context(system_u:object_r:postfix_bounce_exec_t,s0)
 /usr/lib(64)?/postfix/pipe	-- gen_context(system_u:object_r:postfix_pipe_exec_t,s0)
 /usr/lib(64)?/postfix/virtual -- gen_context(system_u:object_r:postfix_virtual_exec_t,s0)
+/etc/network/if-down.d/postfix -- gen_context(system_u:object_r:initrc_exec_t,s0)
+/etc/network/if-up.d/postfix -- gen_context(system_u:object_r:initrc_exec_t,s0)
 ')
 /etc/postfix/postfix-script.* -- gen_context(system_u:object_r:postfix_exec_t,s0)
 /etc/postfix/prng_exch	--	gen_context(system_u:object_r:postfix_prng_t,s0)