  VMailMgr FAQ
  Bruce Guenter  <mailto:bruceg@em.ca>, Dan Kuykendall
  <mailto:dan@kuykendall.org>
  v1.0, 23 April 2000

  VMailMgr Frequently Asked Questions.
  ______________________________________________________________________

  Table of Contents


  1. Building and Installing

     1.1 What compiler and libraries do I need to build vmailmgr?
     1.2 Does vmailmgr work with shadow passwords?
     1.3 Does vmailmgr support IMAP?

  2. Setup and Configuration

     2.1 What other software is needed to run vmailmgr?
     2.2 How do I record the output of vmailmgrd with syslog?
     2.3 How do I record the output of vmailmgrd with multilog?
     2.4 How do I setup VMmailMgr IMAP support?
     2.5 Upgrading from Previous Versions
     2.6 How do I configure qmail+patches to use vmailmgr for POP?
     2.7 How do I allow clients to relay SMTP through me?

  3. Usage

     3.1 I can only use one IP address. How do I log in as a virtual user?
     3.2 How do I get all misdirected mail sent to me?

  4. Troubleshooting

     4.1 Bind error message from vmailmgrd.
     4.2 Error sending to an alias: qmail-queue exited with an error!
     4.3 Running vmailmgrd fails.
     4.4 POP3 or IMAP logins take 30 seconds or longer.

  5. Miscellaneous

     5.1 How do I get in contact with other users?
     5.2 Are development version of vmailmgr available anywhere?
     5.3 How does incoming email get handled?
     5.4 How does outgoing email get handled?
     5.5 What about security of CGI and PHP functions?
     5.6 What are the differences between vmailmgr and vpopmail?


  ______________________________________________________________________

  1.  Building and Installing

  1.1.  What compiler and libraries do I need to build vmailmgr?

  You will need a working C and C++ compiler and linker. You will not
  need any C++ libraries.  The package is being developed under Linux
  using egcs and glibc version 2, and may rely on some gcc/g++
  extensions.

  1.2.  Does vmailmgr work with shadow passwords?

  This package should work without changes both with and without shadow
  passwords as long as the shadow password libraries are present when
  this package is built. The `configure' script will detect what method
  of shadow passwords are being used and the programs will be built
  accordingly.

  1.3.  Does vmailmgr support IMAP?

  Yes, vmailmgr supports Courier-IMAP.  Some minor steps are needed to
  make them work, the steps are in the next section of this file.

  2.  Setup and Configuration

  2.1.  What other software is needed to run vmailmgr?

  VMailMgr is based around qmail's handling of virtual users, and as
  such requires qmail for its operation. If you wish to use the `init'
  file to start/stop vmailmgrd or are installing the RPM package,
  supervise-scripts version 2.2 (or later, available at
  <http://em.ca/~bruceg/supervise-scripts/>) and daemontools 0.60 (or
  later, available at  <http://em.ca/~bruceg/rpms/daemontools/>)
  packages are required.  If you need to use the vmailmgrd daemon, you
  will also need the unixserver program, from the ucspi-unix package,
  available at  <http://em.ca/~bruceg/ucspi-unix/>.

  If you want to use the autoresponse feature, I recommend the use of my
  own autoresponder program, qmail-autoresponder available at
  <http://em.ca/~bruceg/qmail-autoresponder/>.

  2.2.  How do I record the output of vmailmgrd with syslog?

  Output from vmailmgrd can be recorded by either splogger (part of
  qmail) or with the logger that comes with several flavours of UNIX. To
  use splogger, pipe the output of vmailmgrd into the command `splogger
  vmailmgrd'. This will timestamp each entry and tag them with the word
  `vmailmgrd'. By default, splogger logs to facility 2 (mail). To use
  logger, pipe the output of vmailmgrd into the comamand `logger -t
  vmailmgrd -p mail.notice'. See the respective man pages of these two
  programs for more information.

  Note: The use of syslog for logging messages is strongly discouraged
  due to problems with inefficent and buggy implementation of syslog.

  2.3.  How do I record the output of vmailmgrd with multilog?

  Make a directory into which the output will go, for example
  `/var/log/vmailmgrd'. Pipe the output of vmailmgrd into the command
  `multilog t /var/log/vmailmgrd'. See the documentation for multilog
  for more information on how to adjust its output.

  2.4.  How do I setup VMmailMgr IMAP support?

  VMailMgr supports Courier-IMAP, but Courier-IMAP does not auto detect
  VMailMgr.  This means that some minor work is required for making the
  two work together.

  o  You must copy `/usr/local/bin/authvmailmgr` to `/usr/lib/courier-
     imap/libexec/authlib/authvmailmgr`.

  o  Then modify the `AUTHMODULES` statement in `/usr/lib/courier-
     imap/etc/imapd.config` and add `authvmailmgr` as the first
     authentication module.

  2.5.  Upgrading from Previous Versions

  If you are upgrading from an older version, you may need to make some
  changes to your system before or after doing the upgrade. The
  following table outlines the necessary changes. Note that you need to
  follow the instructions for all later versions of the software.

  If you are upgrading from version:

     0.96.6 or earlier
        The `vmailmgrd' daemon needs to be run by unixserver, as opposed
        to being a stand-alone program previously.

     0.96.2 or earlier
        Make sure the `vmailmgrd' daemon and vmailmgr CGIs are disabled
        before upgrading, and upgrade them along with the main package.
        Changes were made to the daemon interface that will cause adding
        users and aliases to flake out. As well, the listdomain
        interface was completely redone.


     0.94 or earlier, using the POP bulletin facility
        The POP bulletin facility has been moved into a stand-alone
        program that needs to be executed through `checkvpw-postsetuid'.


     0.93 or earlier
        If you do not use the CGIs, you no longer need to run the
        `vmailmgrd' daemon.


     0.92.2 or earlier
        The configuration changed from reading a single file to reading
        a set of files in a directory. Read the configuration
        documentation and run the program `vconf2dir'.


     0.90.2 or earlier
        The name of the user to which mail to an unknown user is
        delivered changed from `*' to `+'. If you were using this
        feature, either change all your domains to accomodate this
        change, or set the `default-username' config file to contain
        `*'.


     0.88 or earlier
        The file format of the virtual password tables has changed from
        plain text files to CDB tables. You will need to suspend local
        deliveries before upgrading, and run the program `vpasswd2cdb'
        as each base user after upgrading, before re-enabling local
        deliveries.

  2.6.  How do I configure qmail+patches to use vmailmgr for POP?

  Put the string `checkvpw' into the file
  `/etc/qmail/control/checkpassword' and restart pop3d by typing
  `/etc/rc.d/init.d/pop3d restart'.

  2.7.  How do I allow clients to relay SMTP through me?

  Download and install relay-ctrl from  <http://em.ca/~bruceg/relay-
  ctrl/>.  It works with vmailmgr, for both POP3 and IMAP clients.

  3.  Usage

  3.1.  I can only use one IP address. How do I log in as a virtual
  user?

  There are two ways to log in without using multiple IP addresses.

  The first way is to log in as `userSEPvirtual.domain.org', where
  `user' is the mailbox name of the virtual user, SEP is one of `@' or
  `:' (by default, this is configurable in the `/etc/vmailmgr/'
  directory), and `virtual.domain.org' is the virtual domain's name, as
  listed in `/var/qmail/control/virtualdomains'.

  The second way is to use the internal form of the mailbox name -- that
  is, `baseuser-user', where `user' is the same as above, and `baseuser'
  is the username of the managing user.

  Example: `/var/qmail/control/virtualdomains' contains

    testdomain.org:testuser


  User `testuser' exists, and has set up a virtual mailbox with the name
  `v'. The `separators' variable in `/etc/vmailmgr/' contains `@:'. This
  virtual user could log in as `v@testdomain.org', `v:testdomain.org',
  or `testuser-v'.



  3.2.  How do I get all misdirected mail sent to me?

  In the `vmailmgr/' configuration directory, there is an entry called
  `default-username'. If mail to a virtual domain does not match any
  users or aliases in that domain, it is delivered to the name listed in
  this configuration item if it exists (which defaults to `+'). To make
  this deliver to you, simply type:

    vaddalias + me



  4.  Troubleshooting

  4.1.  Bind error message from vmailmgrd.

  If vmailmgrd reports `vmailmgrd: bind: no such file or directory' when
  you start it up, it means that can't create its socket file.  By
  default, it will try to create the socket file `/tmp/.vmailmgrd'. You
  must ensure that `/tmp' is writable, or that the socket is created in
  some other place by setting `socket-file' in the configuration.

  4.2.  Error sending to an alias: qmail-queue exited with an error!

  If qmail reports "deferral: vdeliver: qmail-queue exited with an
  error!", check where your qmail is installed.  On Debian systems, you
  will need to type "ls -s /usr/sbin /var/qmail/bin", since they've
  installed the qmail binaries into /usr/sbin.

  4.3.  Running vmailmgrd fails.

  When run by itself, vmailmgrd will report "Timed out waiting for
  remote".  vmailmgrd needs to be run from unixserver, part of the
  ucspi-unix package available at  <http://em.ca/~bruceg/ucspi-unix/>.

  4.4.  POP3 or IMAP logins take 30 seconds or longer.

  This is almost certainly a DNS lookup problem.  Make sure that DNS
  lookups aren't timing out, that lookups on all your IP addresses
  aren't failing, and that you can lookup remote addresses as well.

  If you are using 'tcpserver' for the head end to qmail-pop3d, then you
  may want to the following 2 switches to the command line: -R and -H.
  The former prevents tcpserver from attempting to obtain TCPREMOTEINFO
  from the remote host.  This eliminates an "ident" lookup that may be
  being blocked or silently dropped by a firewall.  The latter prevents
  tcpserver from doing a DNS lookup on the remote IP.
  5.  Miscellaneous

  5.1.  How do I get in contact with other users?

  There is a mailing list run by the author. To subscribe, send an e-
  mail (content and subject line is ignored) to  <mailto:vmailmgr-
  subscribe@lists.em.ca>.

  Remember that if you have a problem that you want us to diagnose, we
  need to know the following important details:

  1. The output of `qmail-showctl`

  2. The contents of the vmailmgrd log for the attempt you are trying to
     diagnose

  3. The contents of the qmail and smtpd logs for a failed delivery
     attempt

  4. The contents of the pop3d logs for a failed login attempt

  5. The complete command line with which vmailmgrd and qmail-pop3d was
     invoked

     Please do not contact the author directly with vmailmgr questions.

  5.2.  Are development version of vmailmgr available anywhere?

  Yes, they are available through anonymous CVS.  To access the CVS
  server, set your CVSROOT to :pserver:cvs@bruce-
  guenter.dyndns.org:/CVS, log in with an empty password, and check out
  the vmailmgr module.

  5.3.  How does incoming email get handled?

  Incoming email is first received by the qmail SMTP daemon and inserted
  into the qmail queue. Then `qmail-send' examines the email envelope
  (which details the recipient address or addresses) to determine how to
  dispatch the message. It looks up the domain name of each recipient in
  `/var/qmail/control/virtualdomains', and prefixes the user name with
  the string that it finds. It then looks up the resulting user name in
  the system password table (or in `/var/qmail/users/cdb' if it exists)
  to find the base user name and home directory (which I will call
  `$HOME'). It then looks for the file `$HOME/.qmail-VIRTUAL'. If that's
  not found, it looks for the file `$HOME/.qmail-default', which will
  contain an instruction to pipe the message to `vdeliver'.

  This is where vmailmgr first enters the picture. The virtual user name
  is sent to `vdeliver' through environment variables. It looks in the
  configuration files (in `$HOME/.vmailmgr' and then in `/etc/vmailmgr')
  to determine the location of the password table, and looks up the
  virtual user name in the table to determine delivery instructions. If
  the name is not found, the message is bounced and delivery ends.
  Otherwise, it then looks for the `vdeliver-predeliver' script in the
  configuration directories (in reverse order) and executes any that are
  found. It then delivers the message to all the listed destinations --
  an optional mailbox directory and zero or more forwarding addresses.
  Finally, it looks for the `vdeliver-postdeliver' script and executes
  any that are found.

  5.4.  How does outgoing email get handled?

  Outgoing email is not handled by vmailmgr. For details on outgoing
  email handling, check the qmail documentation.


  5.5.  What about security of CGI and PHP functions?

  The socket used by the daemon is a UNIX-domain socket (as opposed to
  Internet-domain), meaning you need local access on the computer to
  open up a connection.  The path for this socket is run-time
  configurable.

  The daemon forks a new connection for each connection, up to a
  configurable maximum (at which point it stops listening, IIRC, I
  should verify this).  The idea of threading has been completely
  discarded to avoid a bug in a command creeping in and makeing the
  whole server break.

  The protocol spoken over the socket is explicitly bounded to at most
  64kB of data, and all data is prefixed by a size.  Static-sized
  buffers are only used with static-sized reads, and therefore can't be
  overflowed with stack-smashing tricks.

  The daemon commands setuid to the appropriate user as soon as the base
  user has been verified, to avoid doing any more than necessary as
  root, as well as to avoid the possibility of tricking the daemon into
  reading a file another user wouldn't normally have access to.

  To help avoid DoS on the local computer, a 1-second alarm is set as
  soon as the connection is received, and is only cleared once all the
  data has been read.  If it takes longer than 1 second to read the data
  from the socket, the server process exits.

  5.6.  What are the differences between vmailmgr and vpopmail?

  The primary difference between vmailmgr and vpopmail is the use of
  base users.  With vmailmgr there is one base user for each virtual
  domain.  With vpopmail, there is one base user for the entire virtual
  domain system.
































