--- postfix-2.9.4/src/virtual/maildir.c.orig	2012-12-07 08:38:15.031182187 +0100
+++ postfix-2.9.4/src/virtual/maildir.c	2012-12-07 08:39:11.291180202 +0100
@@ -972,19 +972,19 @@
         if (*var_virt_maildir_limit_message_maps != 0 && (limit_message = mail_addr_find(virtual_maildir_limit_message_maps, state.msg_attr.user, (char **) NULL)) != 0) {
             errno = errnored;
             if (errno == EFBIG) {
-                dsb_simple(why, "5.2.2", limit_message);
+                dsb_simple(why, "5.2.2", "%s", limit_message);
             }
             if (errno == EDQUOT) {
-                dsb_simple(why, "4.2.2", limit_message);
+                dsb_simple(why, "4.2.2", "%s", limit_message);
             }
         }
         else {
             errno = errnored;
             if (errno == EFBIG) {
-                dsb_simple(why, "5.2.2", var_virt_maildir_limit_message);
+                dsb_simple(why, "5.2.2", "%s", var_virt_maildir_limit_message);
             }
             if (errno == EDQUOT) {
-                dsb_simple(why, "4.2.2", var_virt_maildir_limit_message);
+                dsb_simple(why, "4.2.2", "%s", var_virt_maildir_limit_message);
             }
         }