Enabled default mailboxes

config/dovecot/15-mailboxes.conf

@@ -47,6 +47,7 @@ namespace inbox {
   # These mailboxes are widely used and could perhaps be created automatically:
   mailbox Drafts {
     special_use = \Drafts
+    auto = subscribe
   }
   mailbox Spam {
     special_use = \Junk
@@ -54,15 +55,18 @@ namespace inbox {
   }
   mailbox Junk {
     special_use = \Junk
+    auto = subscribe
   }
   mailbox Trash {
     special_use = \Trash
+    auto = subscribe
   }
 
   # For \Sent mailboxes there are two widely used names. We'll mark both of
   # them as \Sent. User typically deletes one of them if duplicates are created.
   mailbox Sent {
     special_use = \Sent
+    auto = subscribe
   }
   mailbox "Sent Messages" {
     special_use = \Sent