In the Gmail case Wl stores this flag only for messages with status
"u" (unseen, cached), but not for "U" (unseen, uncached) and "N"
(new, uncached). This is a bug in Google's imap server, but, well, fix it
in our mail client...
number strategy
&optional section
outbuf unseen)
+ (elmo-imap4-set-flag folder (list number) "\\Seen")
(elmo-imap4-message-fetch folder number strategy section outbuf unseen))
(luna-define-method elmo-message-fetch-field ((folder elmo-imap4-folder)