4 (The upper item has the greater priority or feasibility... maybe :-)
7 o full-text search of messages (plain, or hooking up with Namazu)
8 o original icons and logos
10 o speed-up of filtering
11 o regular expression support at filtering
13 o parallel processing between sending-receiving and others
14 o support for some formats other than MH and mbox (ex. Maildir)
15 o priority (Priority:, X-Priority:, X-MSMail-Priority:)
16 o notification of reception (Disposition-Notification-To:)
17 o customization of key bindings
18 o customization of toolbar
22 o console mode interface
24 o mailing list manager
25 o inline image display on multipart MIME
27 o make the code cleaner
28 o make the process faster
29 o make the dubious English much decent :)
31 Partially implemented features
32 ==============================
33 . make the network related code much decent
34 (processing of time out, multi-threading etc.)
36 . full internationalization
40 . display of HTML messages (composition of HTML message is not scheduled :-P)
41 . progress display of time-consuming processes
42 . modification of display color
46 * multipart MIME (attachments of files)
49 * management of read message on POP server by UIDL
52 * reconnection when connection to news server is broken
54 * preservation of position or size of window
55 * external editor support
57 * extension of quotation format
58 * assignation of location of mail folder
59 * account selection on composition window
60 * posting to newsgroups
61 * completion of mail address
62 * prohibition of multiple execution (with Unix domain socket)
63 * periodical check of newly arrived mails
64 * designate the displayed headers
65 * user-defined headers
66 * list view of newsgroups and subscription of groups from there