faq

Vovida 社区开源的 SIP 协议源码

		   IMAP TOOLKIT FREQUENTLY ASKED QUESTIONS
			Last Updated: 16 October 2000

GENERAL QUESTIONS:

Q: Is this software Y2K compliant?
A: Please read the files Y2K and calendar.txt.


Q: How can I use a C++ compiler with this software?
A: If you are building an application using the c-client library, use the
    new c-client.h file instead of including the other include files.  I
    think that c-client.h should define away all the troublesome names that
    conflict with C++.


Q: Can I set up a POP or IMAP server on Windows 2000, Windows 95 and 98?
A: Yes.  Refer to the NT specific notes in files CONFIG and BUILD.  Also,
    you *must* set up CRAM-MD5 authentication, as described in md5.txt.
    There is no file access control on Windows 9x, so you probably will
    have to do modifications to env_unix.c to prevent people from hacking
    others' mail.
   Note, however, that the server is not plug and play the way it is for
    UNIX.


Q: I have a Windows system.  Why isn't the server plug and play for me?
A: There is no standard for how mail is stored on NT; nor a single standard
    SMTP server.  So there's no default by which to make assumptions.  As
    the software is set up, it assumes that the each user has an NT login
    account and private home directory, and that mail is stored on that
    home directory as files in one of the popular UNIX formats.  It also
    assumes that there is some tool equivalent to inetd on UNIX that does
    the TCP/IP listening and server startup.
   Basically, unless you're an email software hacker, you probably want
    to look elsewhere if you want IMAP/POP servers for Windows.


Q: Can I set up a POP or IMAP server on Windows 3.1 or DOS?
Q: Can I set up a POP or IMAP server on Macintosh?
Q: Can I set up a POP or IMAP server on VAX/VMS?
A: It's just a small matter of programming.  Have fun.


Q: Can I set up a POP or IMAP server on TOPS-20?
A: You have a TOPS-20 system?  Cool.
   If IMAP2 (RFC 1176) is good enough for you, you can use MAPSER which
    is about the ultimate gonzo pure TOPS-20 extended addressing assembly
    language program.  Maybe someone will hack it to do IMAP4rev1 some day.
   Or you can port the IMAP server from this IMAP toolkit to it.  All
    that you need for a first stab is to port the MTX driver.  That'll
    probably be just a couple of hours of hacking.
  

Q: What is the status of internationalization?
A: The IMAP toolkit is partially internationalized and multilingualized.
    In particular, searching is supported in the following charsets:
     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-8859-10, ISO-8859-11, ISO-8859-13, ISO-8859-14, ISO-8859-15,
     KOI8-R, KOI8-U (alias KOI8-RU), TIS-620, VISCII,
     ISO-2022-JP, ISO-2022-KR, ISO-2022-CN, ISO-2022-JP-1, ISO-2022-JP-2,
     GB2312 (alias CN-GB), CN-GB-12345, BIG5 (alias CN-BIG5),
     EUC-JP, EUC-KR, Shift_JIS, Shift-JIS, KS_C_5601-1987, KS_C_5601-1992,
     WINDOWS_874, WINDOWS-1250, WINDOWS-1251, WINDOWS-1252, WINDOWS-1253,
     WINDOWS-1254, WINDOWS-1255, WINDOWS-1256, WINDOWS-1257, WINDOWS-1258.
    All ISO-2022-?? charsets are treated identically, and support ASCII,
     JIS Roman, hankaku katakana, ISO-8859-[1 - 10], TIS, 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.
    There is no support for localization (e.g. non-English error messages)
     at the present time, but such support is planned.


Q: Are hierarchical mailboxes supported?
A: Yes.  However, there is one important caveat.
   Some mailbox formats, including the default which is the traditional UNIX
    mailbox format, are stored as a single file containing all the messages.
    UNIX does not permit a name in the filesystem to be both a file and a
    directory; consequently you can not have a sub-mailbox within a mailbox
    that is in one of these formats.
   This is not a limitation of the software; this is a limitation of UNIX.
    For example, there are mailbox formats in which the name is a directory
    and each message is a file within that directory; these formats support
    sub-mailboxes within such mailboxes.  However, for technical reasons, the
    "flat file" formats are generally preferred since they perform better.
    Read imap-2000/docs/formats.txt for more information on this topic.
   It is always permissible to create a directory that is not a mailbox, and
    have sub-mailboxes under it.  The easiest way to create a directory is to
    create a new mailbox inside a directory that doesn't already exist.  For
    example, if you create "Mail/testbox" on UNIX, the directory "Mail/" will
    automatically be created and then the mailbox "testbox" will be created as
    a sub-mailbox of "Mail/".
   It is also possible to create the name "Mail/" directly.  Check the
    documentation for your client software to see how to do this with that
    software.
   Of course, on Windows systems you would use "\" instead of "/".

Q: Are "dual-use" mailboxes supported?
Q: Can I have a mailbox that has both messages and sub-mailboxes?
A: See the answer to the question, "Are hierarchical mailboxes supported?"


Q: What is the difference between "mailbox" and "folder"?
A: The term "mailbox" is IMAP-speak for what a lot of software calls a "folder"
    or a "mail folder".  However, "folder" is often used in other contexts to
    refer to a directory, for example, in the graphic user interface on both
    Windows and Macintosh.
   A "mailbox" is specifically defined as a named object that contains
    messages.  It is not required to be capable of containing other types of
    objects including other mailboxes; although some mailbox formats will
    permit this.
   In IMAP-speak, a mailbox which can not contain other mailboxes is called a
    "no-inferiors mailbox".  Similarly, a directory which can not contain
    messages is not a mailbox and is called a "no-select name".

BUILD AND CONFIGURATION QUESTIONS:

Q: How do I configure the IMAP and POP servers on UNIX?
Q: I built and installed the servers according to the BUILD instructions.
    It can't be that easy.  Don't I need to write a config file?
A: For ordinary "vanilla" UNIX systems, this software is plug and play; just
    build it, install it, and you're done.  If you have a modified system,
    then you may want to do additional work; most of this is to a single
    source code file (env_unix.c on UNIX systems).  Read the file CONFIG
    for more details.
   Yes, it's that easy.  There are some additional options, such as SSL or
    Kerberos, which require additional.  See the relevant questions below.


Q: How do I make the IMAP and POP servers look for INBOX at some place
    other than the mail spool directory?
Q: How do I make the IMAP server look for secondary folders at some place
    other than the user's home directory?
A: Please read the file CONFIG for discussion of this and other issues.


Q: Can I use SSL?
Q: Can I use TLS and the STARTTLS facility?
A: Yes.  imap-2000 supports SSL client functionality for IMAP, POP3, SMTP,
    and NNTP; and SSL and TLS server functionality for IMAP and POP3.  This
    is available on UNIX, and 32-bit Windows.
   UNIX SSL build requires that a third-party software package, OpenSSL, be
    installed on the system first.  Read imap-2000/docs/SSLBUILD for more
    information.
   SSL is supported via undocumented Microsoft interfaces in Windows 9x and
    NT4; and via standard interfaces in Windows 2000 and Windows Millenium.
   

Q: Can I use CRAM-MD5 authentication?
Q: Can I use APOP authentication?
A: CRAM-MD5 authentication is enabled in the IMAP and POP3 client code on
    all platforms.  Read md5.txt to learn how to set up CRAM-MD5 and APOP
    authentication on UNIX and NT servers.
   There is no support for APOP client authentication.


Q: Can I use RPOP authentication?
A: There is no support for RPOP authentication.


Q: Can I use Kerberos V5?
A: Yes.  imap-2000 supports client and server functionality on UNIX and 32-bit
    Windows.
   Kerberos V5 is supported by default in Windows 2000 and Windows Millenium
    builds:
     nmake -f makefile.w2k
   Other builds require that a third-party software package, MIT Kerberos, be
    installed on the system first.
   To build with Kerberos V5 on UNIX, include EXTRAAUTHENTICATORS=gss in the
    make command line, e.g.
     make lnp EXTRAAUTHENTICATORS=gss
   To build with Kerberos V5 on Windows 9x and NT4, use the "makefile.ntk"
    file instead of "makefile.nt":
     nmake -f makefile.ntk


Q: Can I use Kerberos V4?
A: Kerberos V4 is not supported.  Kerberos V4 client-only contributed code
    is available as:
     ftp://ftp.cac.washington.edu/mail/kerberos4-patches.tar.Z
   This is a patchkit which must be applied to the IMAP toolkit according
    to the instructions in the patchkit's README.  I can not promise that
    this code works.


Q: Can I use PAM for plaintext passwords?
A: On Linux systems, use the lnp port, e.g.
     make lnp
   On Solaris systems and other systems with defective PAM implementations,
    build with PASSWDTYPE=pmb, e.g.
     make sol PASSWDTYPE=pmb
   On all other systems, build with PASSWDTYPE=pam, e.g
     make foo PASSWDTYPE=pam
   If you build with PASSWDTYPE=pam and authentication does not work, try
    rebuilding (after a "make clean") with PASSWDTYPE=pmb.


Q: Can I use AFS for plaintext passwords?
A: Build with PASSWDTYPE=afs, e.g
     make sol PASSWDTYPE=afs


Q: Can I use DCE for plaintext passwords?
A: Build with PASSWDTYPE=dce, e.g
     make sol PASSWDTYPE=dce


Q: Can I use the CRAM-MD5 database for plaintext passwords?
A: The CRAM-MD5 password database is automatically used for plaintext
    password if it exists.
   Note that this gives you the worst of both worlds -- plaintext passwords
    over the network and plaintext passwords stored on the server!  You
    probably don't want to do this unless all access is through SSL.  It
    is recommended that you disable plaintext passwords (see the next
    question).


Q: Can I disable plaintext passwords?
A: Server-level plaintext passwords can be disabled by setting
    PASSWDTYPE=nul, e.g.
     make lnx EXTRAAUTHENTICATORS=gss PASSWDTYPE=nul
   Note that you must have a CRAM-MD5 database installed or specify at least
    one EXTRAAUTHENTICATOR, otherwise it will not be possible to log in to
    the server.
   When plaintext passwords are disabled, the IMAP server will advertise
    the LOGINDISABLED capability and the POP3 server will not advertise
    the USER capability.


Q: Is there support for S/Key or OTP?
A: There is currently no support for S/Key or OTP.  There may be an OTP
    SASL authenticator available from third parties.


Q: Is there support for NTLM or SPA?
A: There is currently no support for NTML or SPA, nor are there any plans
    to add such support.  In general, we avoid vendor-specific mechanisms.


Q: Is there support for qmail and the maildir format?
A: There is no support for qmail or the maildir format in our distribution,
    nor are there any plans to add such support.  There may be maildir
    support available from third parties.

OPERATIONAL QUESTIONS:

Q: How can I enable anonymous IMAP logins?
A: Create the file /etc/anonymous.newsgroups.  At the present time, this
    file should be empty.  This will permit IMAP logins as anonymous as
    well as the ANONYMOUS SASL authenticator.  Anonymous users have access
    to mailboxes in the #news., #ftp/, and #public/ namespaces only.