gentoo-overlay/mail-mta/exim/files/exim-4.20-maildir.patch

diff -urN ./exim-4.20.orig/src/configure.default exim-4.20/src/configure.default
--- ./exim-4.20.orig/src/configure.default	2003-06-27 16:48:22.000000000 -0700
+++ exim-4.20/src/configure.default	2003-06-27 16:52:20.000000000 -0700
@@ -451,7 +451,9 @@
 
 local_delivery:
   driver = appendfile
-  file = /var/mail/$local_part
+#  file = /var/mail/$local_part
+  directory = /home/$local_part/.maildir
+  maildir_format
   delivery_date_add
   envelope_to_add
   return_path_add