[Dovecot] Caseless folder delivery?

[Jay Levitt]

I'm using exim4 to deliver into dovecot 1.1, and using plus-addressing to 
deliver mailing lists directly to appropriate folders in my "lists" mailbox. 
  I created a file called /folder-map.lists that looks like

## folder-map.lists
dovecot: Dovecot
lpedge: Linux PowerEdge

... and so on.  So mail to lists-lpedge at jay.fm goes to the "Linux PowerEdge" 
folder.

The one annoying thing: I'd like to avoid creating explicit folder-map 
entries where the plus-address suffix is identical an existing folder name. 
  That *almost* works, but I like to name my folders with appropriate 
capitalization, and deliver doesn't seem to have a way to do "caseless" 
delivery.

For instance, ideally, I wouldn't have to create the "dovecot: Dovecot" 
entry; mail to my lists-dovecot at jay.fm address would go into the "Dovecot" 
folder.

I can't figure out how to do this.  Is there a way to do that using deliver? 
  Could there be?  Relevant portions of the exim configuration follow. 
(And, p.s., am I using the new -a and -m options correctly?  Are they used 
for anything yet?)

Jay Levitt



## exim.conf

...begin routers

ORIG_FOLDER = ${substr_1:$local_part_suffix}
FOLDER_MAP  = /etc/exim/folder-map.$local_part
MAPPED_FOLDER = ${lookup{ORIG_FOLDER}lsearch{FOLDER_MAP}{$value}{ORIG_FOLDER}}


# Mailboxes whose localparts are folders
foldered_mailboxes:
   driver = accept
   local_part_suffix = +* : -*
   local_part_suffix_optional
   local_parts = +foldered_mailboxes
   address_data = user=$local_part folder="MAPPED_FOLDER"
   transport = dovecot_virtual_delivery

...begin transports

dovecot_virtual_delivery:
   driver = pipe
   command = /usr/local/libexec/dovecot/deliver \
         -f $return_path \
         -a $local_part$local_part_suffix@$domain \
         -d ${extract{user}{$address_data}} \
         -m "${extract{folder}{$address_data}}" -n
   message_prefix =
   message_suffix =
   log_output
   return_path_add
   user = vmail