Description of Problem:

In prerelease versions, there was a grayed-out
option on POP3 accounts to leave mail on server
but delete after (fill in) days.  This is a
feature of Outlook that Evolution lacks.  This was
not implemented, and the gray was dropped.  I
suggest it is important to restore.

Rationale:  While IMAP gives good control over
server files, POP3 is far more common in the ISP
world.  POP3's usual model is "fetch and delete".
 But this does not work well when the user
maintains more than one computer; e.g., home and
office.  If mail is deleted before being picked up
by the second computer, that computer won't have
access to the deleted mail.

POP3's common extensions (I presume based on UIDL)
make it feasible for multiple computers to sync
their mail, each fetching only mail that it has
never seen before.  Microsoft Outlook and Qualcomm
Eudora, among others, both provide the "delete
after _ days" option.  This can be set, for
example, to 3 days.  Thus mail retrieved on one
computer (say, home) on Friday evening won't be
deleted until Monday, after the other computer
(say, office) has had a three-day window to also
retrieve it.  Voila, instant synchronization, with
none of the awfulness associated with, say, the
Notes style of replication.

For some odd reason none of the common Linux GUI
mailers (Evolution, Kmail, Sylpheed, Balsa) have
this; I find that it's a show-stopper for not
giving up Windows as a primary mail client system
right now.  (If I've got Linux running, I have to
boot back to Windows every few days to sync the
mail archive.)  I can't imagine that it's all that
difficult, since there's a POP3 extension function
designed to support it.