Merging existing mailboxes to aliases

[Lefteris Tsintjelis]

I am trying to merge all, existing or not, different mailboxes in one 
with the mailbox alias plugin. If I add the following lines, will the 
existing mailboxes automatically merge in one mailbox and corresponding 
links auto create? If not, do I have to do this manually?

   mailbox_alias_new = Spam
   mailbox_alias_new2 = Junk E-mail
   mailbox_alias_new3 = Sent Items
   mailbox_alias_new4 = Sent Messages
   mailbox_alias_new5 = Deleted Items
   mailbox_alias_old = Junk
   mailbox_alias_old2 = Junk
   mailbox_alias_old3 = Sent
   mailbox_alias_old4 = Sent
   mailbox_alias_old5 = Trash

Lefteris