Updated: 31 December 1997

This is a snapshot of development sources of of the IMAP 4.1 toolkit.  It
is updated frequently.

This version supports IMAP4rev1 (RFC 2060).  There are major internal and
external changes from the IMAP2bis version (e.g. imap-3.6, distributed with
Pine 3.9x).  It is extremely unlikely that a program written for the IMAP2bis
verion will build with this version without modifications.  Drivers written
for the IMAP2bis version will definitely need to be rewritten.

Most notable operational changes:
 . The mbox driver is now enabled by default.  If the file "mbox" exists on
    the user's home directory and is in UNIX mailbox format, then when INBOX
    is opened this file will be selected as INBOX instead of the mail spool
    file.  Messages will be automatically transferred from the mail spool file
    into the mbox file.
   To disable this behavior, delete "mbox" from the EXTRADRIVERS list in the
    file .../src/osdep/unix/Makefile and rebuild.
 . IMAP4rev1 protocol is now supported.  The UNIX format support now maintains
    unique identifiers (UIDs) and keyword flags for each message, and keeps an
    invisible message at the start of the file which contains the UID base
    information and a list of assigned keywords.  There is no way to disable
    this behavior, since it would disable IMAP4rev1 support.  This message may
    show up if you access the mailbox as a file using older mail software (e.g.
    Pine 3.9x).  It is invisible with IMAP or POP access, or with access as a
    file using Pine 4.00.
 . Support for additional mailbox formats.
 . No longer keeps entire mailbox in memory for UNIX format files.
 . Multilingual searching of the following charsets are supported:
	US-ASCII, UTF-8, ISO-8859-1, ISO-8859-2, ISO-8859-3, ISO-8859-4,
	ISO-8859-5, ISO-8859-6, ISO-8859-7, ISO-8859-8, ISO-8859-9,
	ISO-2022-JP, ISO-2022-KR, ISO-2022-CN, ISO-2022-JP-1, ISO-2022-JP-2,
	GB2312 (alias CN-GB), BIG5 (alias CN-BIG5), EUC-JP, EUC-KR, Shift_JIS,
	KOI8-R, KOI8-U, TIS-620.
   All ISO-2022-?? charsets are treated identically, and support ASCII,
    JIS Roman, ISO-8859-[1-9], GB 2312, JIS X 0208, JIS X 0212, KSC 5601,
    and planes 1 and 2 of CNS 11643.
   EUC-JP includes support for JIS X 0212 and hankaku katakana.
 . Fast sorting including IMAP server-based sort.
 . Fast ordered-subject threading including IMAP server-based threading.


Most notable programmer/external changes:
 . Additional ports
 . New directory orientation, no separate non-ANSI sources
 . New local file formats mbx and mx
 . The bezerk driver has been retired, and replaced with the new unix driver
    which does not keep a snapshot in memory
 . Many new added ports including NT (Win32 client, NT server)
 . Many new data access functions.
 . Numerous interface changes; look at the .h files for details.
 . There are no known security problems in this version.
 . If you ignored the warnings and used the evil configuration file, its name
    and contents have changed incompatibly.


The following are known problems/deficiencies:
 . Bugs:
   . Case-independent searching only works for the 26 Roman alphabetics and
      not for any other characters.
   . The experimental mx driver has performance problems and shouldn't be used
   . docs/Internal.DOC is out of date again
 . POP client limitations:
   . No SASL authentication/protection mechanisms
   . No POP3 UID support
 . IMAP server limitations:
   . No Kerberos4 server support
 . POP3 server limitations:
   . No SASL authentication/protection mechanisms
 . UNIX and Amiga limitations:
   . Supported local file formats: mbx, mh, mmdf, mtx, mx, news, phile, tenex,
      and unix
   . Sticky UIDs are not supported in the mh, mtx, and tenex drivers
   . Creation of keywords is not supported in the mh, mtx, and tenex drivers
   . Flat file formats (mbx, mmdf, mtx, phile, tenex, unix) do not permit
      mailboxes to have inferior names
 . NT limitations:
   . Supported local file formats: mbx, mtx, tenex, unix
   . Sticky UIDs are not supported in the mtxnt and tenexnt drivers
   . Creation of keywords is not supported in the mtxnt and tenexnt drivers
   . No support for TCP open timeouts
   . Flat file formats (mbx, mtx, tenex, unix) do not permit mailboxes to have
      inferior names
 . DOS limitations:
   . Supported TCPs: B&W, Novell, PC-NFs, PC/TCP, Waterloo, Winsock
   . Supported local file formats: bezerk, mtx
   . Sticky UIDs are not supported on local files
   . Creation of keywords are not supported on local files
   . Bezerk driver is read-only and does not handle LF-only newlines well
   . No support for any TCP timeouts on Waterloo DOS
   . No support for TCP open timeouts on Winsock and generic DOS
   . Flat file formats (bezerk, mts) do not permit mailboxes to have inferior
      names
 . Windows CE limitations:
   . No local file drivers
   . No support for TCP open timeouts
   . Not finished
 . OS/2 limitations:
   . Not finished, does not build
 . Mac limitations:
   . No local file drivers
 . TOPS-20 limitations:
   . No local file drivers
   . No support for any TCP timeouts
 . VMS limitations:
   . Supported TCPs: Multinet, Netlib
   . No local file drivers
   . No support for any TCP timeouts on VMS Netlib
   . No support for TCP open timeouts on VMS Multinet
