Thanks to everyone for your advice. I solved this by re-running eximconfig, modifying it by using the examples people sent, and refering to /usr/doc/exim/spec.txt.
For those who want to convert from mbox to Maildir, here's what I had to do: 1. exim.conf changes: local_delivery: driver = appendfile create_directory = true # new line directory_mode = 700 # new line group = mail mode = 0660 # mode_fail_narrower = false envelope_to_add = true return_path_add = true # file = /var/spool/mail/${local_part} directory = ${home}/Maildir/ # new line address_directory: driver = appendfile no_from_hack check_string = "" # new line prefix = "" suffix = "" maildir_format # new line userforward: driver = forwardfile directory_transport = address_directory # new line file_transport = address_file pipe_transport = address_pipe reply_transport = address_reply no_verify check_ancestor check_local_user file = .forward modemask = 002 filter 2 .muttrc changes: set mbox_type=Maildir (change all mbox refs to point to desired maildirs) (launch mutt and create desired maildirs, including parent Maildir folder, by saving messages to them after setting the mbox_type) Note that mutt supports both mboxes and Maildirs, the mbox_type variable just says which kind it will create when you create a new mailbox. 3. .forward changes: Rewrite filter rules, make sure that every Maildir reference ends with a '/'. NOTES I had no problem changing exim's local_delivery transport because my box is a single-user system. You might want to leave it alone. If your filters have decent defaults, nothing will ever get saved to /var/spool/${local_part} anyway. Several people have offered to proved perl-scripts, etc. for converting mboxes to maildirs. Personally, I find that mutt provides enough tools to do the job handily for small mboxes, for the larger ones I'm going to treat the problem as a python programming excercise. Thanks all, PM -- Paul Mackinney [EMAIL PROTECTED] -- To UNSUBSCRIBE, email to [EMAIL PROTECTED] with a subject of "unsubscribe". Trouble? Contact [EMAIL PROTECTED]