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@setfilename FAQ.info

@settitle Vmailmgr FAQ

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@ifinfo

Copyright @copyright{} 1998 Bruce Guenter

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@titlepage

@title Vmailmgr FAQ

@author Bruce Guenter

@author Dan Kuykendall

@subtitle @today{}

@end titlepage

@ifinfo

VMailMgr Frequently Asked Questions.

@end ifinfo

@c ****************************************************************************

@chapter Building and Installing

@section 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.

@section 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 @code{configure} script will

detect what method of shadow passwords are being used and the

programs will be built accordingly.

@section 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.

@c ****************************************************************************

@chapter Setup and Configuration

@section 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 @code{init}

file to start/stop @code{vmailmgrd} or are installing the RPM package,

supervise-scripts version 2.2 (or later, available at 

@uref{http://untroubled.org/supervise-scripts/})

and daemontools 0.60 (or later, available at 

@uref{http://untroubled.org/rpms/daemontools/})

packages are required.  If you need to use the @code{vmailmgrd} daemon, you 

will also need the @code{unixserver} program, from the ucspi-unix package, 

available at

@uref{http://untroubled.org/ucspi-unix/}.

If you want to use the autoresponse feature, I recommend the use of

my own autoresponder program, @code{qmail-autoresponder} available

at 

@uref{http://untroubled.org/qmail-autoresponder/}.

@section How do I record the output of vmailmgrd with syslog?

Output from @code{vmailmgrd} can be recorded by either @code{splogger} (part of 

qmail) or with the logger that comes with several flavours of UNIX. To use 

@code{splogger}, pipe the output of @code{vmailmgrd} into the command 

@samp{splogger vmailmgrd}. This will timestamp each entry and tag them with the 

word @samp{vmailmgrd}. By default, @code{splogger} logs to facility 2 (mail). To 

use @code{logger}, pipe the output of @code{vmailmgrd} into the command 

@samp{logger -t vmailmgrd -p mail.notice}. 

See the respective man pages of these two programs for more information.

Note: The use of @code{syslog} for logging messages is strongly discouraged

due to problems with inefficent and buggy implementation of @code{syslog}.

@section How do I record the output of vmailmgrd with multilog?

Make a directory into which the output will go, for example

@file{/var/log/vmailmgrd}. Pipe the output of @code{vmailmgrd} into the

command @samp{multilog t /var/log/vmailmgrd}. See the

documentation for @code{multilog} for more information on how to adjust its

output.

@section 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.

@itemize @bullet

@item

You must copy @file{/usr/local/bin/authvmailmgr} to

@file{/usr/lib/courier-imap/libexec/authlib/authvmailmgr}.

@item

Then modify the @code{AUTHMODULES} statement in

@file{/usr/lib/courier-imap/etc/imapd.config} and add

@kbd{authvmailmgr} as the first authentication module.

@end itemize

@section 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.

@subsection Upgrading from version 0.96.6 or earlier

The @code{vmailmgrd} daemon needs to be run by unixserver, as opposed

to being a stand-alone program previously.

@subsection Upgrading from version 0.96.2 or earlier

Make sure the @code{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.

@subsection Upgrading from version 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 @code{checkvpw-postsetuid}.

@subsection Upgrading from version 0.93 or earlier

If you do not use the CGIs, you no longer need to run the

@code{vmailmgrd} daemon.

@subsection Upgrading from version 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 @code{vconf2dir}.

@subsection Upgrading from version 0.90.2 or earlier

The name of the user to which mail to an unknown user is

delivered changed from @samp{*} to @samp{+}. If you were using this

feature, either change all your domains to accomodate this

change, or set the @file{default-username} config file to contain @samp{*}.

@subsection Upgrading from version 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 @code{vpasswd2cdb} as

each base user after upgrading, before re-enabling local

deliveries.

@section How do I configure qmail+patches to use vmailmgr for POP?

Put the string @kbd{checkvpw} into the file

@file{/etc/qmail/control/checkpassword} and restart @code{qmail-pop3d} by

typing @samp{/etc/rc.d/init.d/pop3d restart}.

@section How do I allow clients to relay SMTP through me?

Download and install relay-ctrl from

@uref{http://untroubled.org/relay-ctrl/}.

It works with vmailmgr, for both POP3 and IMAP clients.

@c ****************************************************************************

@chapter Usage

@section 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.

@itemize @bullet

@item

The first way is to log in as @samp{user@var{SEP}virtual.domain.org}, where 

@samp{user} is the mailbox name of the virtual user, @var{SEP} is one of 

@samp{@@} or @samp{:} (by default, this is configurable in the 

@file{/etc/vmailmgr/} directory), and @samp{virtual.domain.org} is the virtual 

domain's name, as listed in @file{/var/qmail/control/virtualdomains}.

@item

The second way is to use the internal form of the mailbox name --

that is, @samp{baseuser-user}, where @samp{user} is the same

as above, and @samp{baseuser} is the username of the managing

user.

For example, @file{/var/qmail/control/virtualdomains} contains 

@samp{testdomain.org:testuser}, user @samp{testuser} exists,

and has set up a virtual mailbox with the name @samp{v}.

The @var{separators} variable in @file{/etc/vmailmgr/}

contains @samp{@@:}.  This virtual user

could log in as @samp{v@@testdomain.org},

@samp{v:testdomain.org}, or @samp{testuser-v}.

@end itemize

@section How do I get all misdirected mail sent to me?

In the @file{vmailmgr/} configuration directory, there is an

entry called @file{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 @samp{+}). To make this deliver to you,

simply type:

@example

vaddalias + me

@end example

@section How can I put system accounts in a virtual domain?

System accounts are those listed in @file{/etc/password} (or 

@file{/var/qmail/users/cdb}). 

The system accounts are accessable, either though SMTP or POP3 or IMAP, as 

@samp{name@@@var{DOMAIN}}, where @var{DOMAIN} is listed in

@file{/var/qmail/control/locals}.

Virtual accounts exist only as an artifact of vmailmgr management.

They are accessable as @samp{name@@@var{DOMAIN}}, where @var{DOMAIN} is listed 

in @file{/var/qmail/control/virtualdomains}.

You @strong{cannot} mix accounts within a domain between system and virtual 

domains.  If the domain is in @file{control/locals}, all accounts for that 

domain must be system accounts.  If it is in @file{control/virtualdomains}, all 

accounts for that domain must be virtual accounts.  Also, @file{control/locals} 

overrides @file{control/virtualdomains}: if the domain is in @file{locals}, 

@file{virtualdomains} is ignored.

As an aside, if the domain is neither in @file{locals} nor in

@file{virtualdomains}, qmail will reject incoming messages, and vmailmgr will

treat it as local.

@c ****************************************************************************

@chapter Troubleshooting

@section Bind error message from @code{vmailmgrd}.

If @code{vmailmgrd} reports 

@quotation

vmailmgrd: bind: no such file or directory

@end quotation 

when you start it up, it means that can't create its socket file.  By default, 

it will try to create the socket file @file{/tmp/.vmailmgrd}. You must ensure 

that @file{/tmp/} is writable, or that the socket is created in some other place 

by setting @var{socket-file} in the configuration.

@section Error sending to an alias: @code{qmail-queue} exited with an error!

If qmail reports

@quotation

deferral: vdeliver: qmail-queue exited with an error!

@end quotation

check where your qmail is installed.  On Debian systems,

you will need to type @samp{ls -s /usr/sbin /var/qmail/bin},

since they've installed the qmail binaries into @file{/usr/sbin}.

@section Running @code{vmailmgrd} fails.

When run by itself, @code{vmailmgrd} will report

@quotation

Timed out waiting for remote

@end quotation

@code{vmailmgrd} needs to be run from @code{unixserver}, part of the ucspi-unix

package available at

@uref{http://untroubled.org/ucspi-unix/}.

@section 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 @code{tcpserver} for the head end to @code{qmail-pop3d}, then 

you may want to add the following 2 switches to the command line: @samp{-R} and 

@samp{-H}.  The former prevents @code{tcpserver} from attempting to obtain 

@var{TCPREMOTEINFO} from the remote host.  This eliminates an @code{ident} 

lookup that may be being blocked or silently dropped by a firewall. The latter 

prevents @code{tcpserver} from doing a DNS lookup on the remote IP.

@c ****************************************************************************

@chapter Miscellaneous

@section 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

@email{vmailmgr-subscribe@@lists.untroubled.org}.

Remember that if you have a problem that you want us to diagnose, we

need to know the following important details:

@enumerate

@item

The output of @code{qmail-showctl}

@item

The contents of the @code{vmailmgrd} log for the attempt you are

trying to diagnose

@item

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

attempt

@item

The contents of the pop3d logs for a failed login attempt

@item

The complete command line with which @code{vmailmgrd} and @code{qmail-pop3d}

was invoked

@end enumerate

Please do not contact the author directly with vmailmgr questions. 

@section Are development version of vmailmgr available anywhere?

Yes, they are available through anonymous CVS.

To access the CVS server, set your @code{CVSROOT} to

@kbd{:pserver:cvs@@bruce-guenter.dyndns.org:/CVS}, log in with an

empty password, and check out the @code{vmailmgr} module.

@section How does incoming email get handled?

Incoming email is first received by the qmail SMTP daemon and

inserted into the qmail queue. Then @code{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

@file{/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

@file{/var/qmail/users/cdb} if it exists) to find the base user

name and home directory (which I will call @code{$HOME}). It

then looks for the file @file{@code{$HOME}/.qmail-VIRTUAL}. If that's

not found, it looks for the file @file{@code{$HOME}/.qmail-default},

which will contain an instruction to pipe the message to

@code{vdeliver}.

This is where vmailmgr first enters the picture. The virtual user

name is sent to @code{vdeliver} through environment variables. It looks

in the configuration files (in @file{@code{$HOME}/.vmailmgr} and then

in @file{/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 @code{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 @code{vdeliver-postdeliver}

script and executes any that are found.

@section How does outgoing email get handled?

Outgoing email is not handled by vmailmgr. For details on outgoing

email handling, check the qmail documentation.

@section 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 making 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.

@section 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.

@contents

@bye