Add special folder Archives to map to Archive

conf/dovecot-mailboxes.conf

@@ -50,6 +50,9 @@ namespace inbox {
   # with the \Sent attribute, just in case clients don't agree about which
   # they're using. We'll keep that, plus add Junk as an alterative for Spam.
   # These are not auto-created.
+  mailbox "Archives" {
+    special_use = \Archive
+  }
   mailbox "Sent Messages" {
     special_use = \Sent
   }