Installation

Upgrading from an earlier version

Follow the general installation instructions, below, in order to upgrade an existing installation. You just need to make sure that the options to the configure script are the same as for the previous version. You may specify additional options as well, that are new to this release.

Upgrating from versions prior to 5.0

There are two major changes in version 5.0. Starting with 5.0, the authentication library that used to be a part of SqWebMail's source has been spun off into a standalone authentication library.

You must download and install the Courier authentication library from http://www.courier-mta.org/download.php#authlib before upgrading. Review the documentation in the courier-authlib package for more information.

The second major change is that the default installation directories for SqWebMail have been changed. SqWebMail's default installation is now more closely aligned with standard installation directories used by many other packages based on the GNU toolchain.

Earlier versions of SqWebMail preferred to be installed in /usr/local/share/sqwebmail, with various bits and pieces scattered elsewhere.

Now, SqWebMail's installation layout follows the standards much closer. SqWebMail now implements the usual configuration directives: --prefix, --exec-prefix, --bindir, --datadir, and all the rest. There's only one non-standard default: unless the --prefix option is specified, SqWebMail will be install in /usr/lib/sqwebmail. That's the default installation tree.

Use the following procedure to upgrade the current installation of SqWebMail:

If you're using a package manager, such as RPM or APT, build a new package, and let the package manager figure out what to do. Only one manual step may be required, which the package manager probably won't be able to handle on its own: there might be some left-over custom configuration files in /usr/local/share/sqwebmail. Review the old configuration files, and re-apply any custom changes to the new version's configuration file (which will be in /usr/lib/sqwebmail/etc, or wherever your --sysconfdir option places them). DO NOT just copy the configuration file verbatim. Manually re-apply changes, one at a time.

Otherwise: install the authentication library first. Make sure it is working. Use the authtest program to verify that the authentication library is seeing the existing mail accounts.

Download the new version of SqWebMail, and extract the source code into a new directory. Follow the regular installation instructions up until the "make install" command.

Don't run the "make install" command. Switch to the directory with the old SqWebMail's source code, and run "make uninstall" to remove the old version of SqWebMail. Go back to the new source code, then run "make install", then "make install-configure".

After upgrading, check SqWebMail's older installation directory (usually /usr/local/share/sqwebmail). It'll probably still have some left-over configuration files. Start the new version of SqWebMail, verify that it's working, then nuke /usr/local/share/sqwebmail in order to avoid any future confusion.

Upgrading from versions prior to 4.1

In 4.1, the sqwebmaild, authdaemond and pcpd processes all run in the foreground; they are daemonized by running them under the control of a 'courierlogger' process, which also captures their stderr output and sends it to syslog. The script sqwebmaild.rc takes care of this for you. After upgrading to 4.1 you will need to modify your system startup script to run sqwebmaild.rc start and not to run sqwebmaild start or authdaemond start. See below for more information.

Additional authentication debugging capabilities have been added. See authlib/README.authdebug.html for more information.

A new configuration file, /usr/local/share/sqwebmail/sqwebmaild has been added. Make sure you run make install-configure to create the initial version of this file.

Upgrading from versions prior to 3.0

THIS IS A MAJOR UPGRADE

All mail passwords must be reset when upgrading from versions prior to 3.0. Prior to 3.0 SqWebMail maintained a separate password file for webmail logins. It was automatically initialized with the system password, but then maintained separately. "System password" here refers to whatever password authentication was installed: traditional /etc/passwd file, or MySQL, LDAP, or several other methods.

The separate webmail password file was needed because SqWebmail lacked a convenient way to update the system password. Starting in 3.0, additional code and scripts were added that update the "real" password, and SqWebMail's separate password files are removed. Here is a suggested migration plan:

Note: if you were using the authvchkpw module then you're pretty much off the hook. All except very old versions of SqWebMail had a special authvchkpw module that kept SqWebMail's and vpopmail's passwords in sync. Although you're mostly off the hook, you should still follow these instructions in order to insure a smooth transition.

NOTE: the default configuration settings have been changed to always build the authdaemon module, and build all real authentication modules inside authdaemond. This is true even with the authvchkpw module. authdaemond is needed to support the new password authentication framework.

Upgrading from versions prior to 1.1

Prior to SqWebMail 1.1, each version installed a default set of configuration files. If some custom changes were made to an existing configuration, after installation those changes had to be reapplied.

Beginning with version 1.1 this process is mostly automated. Starting with version 1.1, the configuration files contain additional metadata that allow them to be upgraded automatically. For this to work both the old and the new configuration files must contain this metadata.

Therefore, when upgrading to version 1.1, proceed as follows. Back up the existing configuration, then follow the procedures below to install this version. Because the existing configuration files carry no auto-update metadata, the installation script will rename each configuration file "filename" to "filename.bak", and write a default "filename" in its place. Afterward, edit "filename" and manully reenter all custom changes. Do NOT simply copy the previous configuration file and overwrite the new version, because the autoupdate metadata will be lost.

Note: not all configuration files can be upgraded automatically. Only those configuration files that carry multiple settings ( authdaemonrc, authldaprc, authmysqlrc, and ldapaddressbook) can be automatically upgraded.

Overview

The requirements to install SqWebMail are:

The typical sequence of commands to compile and install SqWebMail is as follows:

 
  ./configure [options - see below]
  make configure-check
  make
  make check
  make install-strip       # Do a make install if this doesn't work
  make install-configure   # Install configuration files.

  # Create post-install cron jobs, and modify system startup script

  # Tweak your web server for MSIE

GNU make is required to compile and install SqWebMail. On xBSD systems GNU make is installed as the "gmake" command. Anywhere this documentation mentions the make command, substitute gmake for make. If you do not have gmake on your system, install it before installing SqWwebMail.

The options to the configure program are as follows:

After running configure, run make configure-check to verify the directories where the CGI and the image files will be installed. make configure-check prints the directories that the configuration script thinks your web server is installed. Rerun configure and use --enable-cgibindir and --enable-imagedir if SqWebMail guessed wrong.

Run make to compile SqWebMail, and make install-stripto install the files. As mentioned before, use make install if make install-strip doesn't work.

WARNING: set your umask to 022 before running make install or make install-strip.

Before running make install-strip, verify the contents of the sendit.sh script, and make sure that your mail transfer agent is corrently invoked.

Modify your system startup script

The following command starts sqwebmail. This command should be added to the system startup script so that sqwebmail automatically starts during the system boot.

/usr/lib/sqwebmail/libexec/sqwebmaild.rc start

"sqwebmaild.rc stop" may also be used to shut down the webmail service.

SELinux

The following extension may be necessary to make SqWebMail work when SELinux kernel extensions are turned on:

allow httpd_sys_script_t var_t:sock_file write;
allow httpd_sys_script_t unconfined_t:unix_stream_socket connectto;

Install the cleancache.pl cron job

After installing, add a cron job that runs the cleancache.pl script at regular intervals (once an hour is fine). cleancache.pl is installed in /usr/lib/sqwebmail/share/sqwebmail. make install will print additional information on installing the cleancache.pl script.

Install configuration files

Run make install-configure to initialize certain configuration files. Some SqWebMail's configuration files carry multiple configuration settings, such as authdaemonrc, ldapaddressbook, and others (see elsewhere in INSTALL for additional information regarding these configuration settings).

For each such configuration file, make install installs filename.dist. make install-configure takes each filename.dist and creates filename. If the previous filename existed, and it contained autoupdate information (SqWebMail 1.1 or later), the existing configuration settings will be preserved, wherever possible. Older configuration files, that are not auto-updatable, will be renamed to filename.bak.

During an autoupdate make install-configure will report on the disposition of each configuration setting. A configuration setting will be preserved as long as it is still valid in the new version of SqWebMail. Obsolete configuration settings are automatically removed. If a configuration setting may not be valid, it is not preserved, but will revert to its default setting from filename.dist. It is recommended that the output of make install-configure be saved (make install-configure >upgrade.log), so that its report can be examined to identify any configuration settings that are flagged for manual action

Post-install configuration

The default configuration script installs the authdaemond process that handles authentication, and it is started by sqwebmaild.rc start

sqwebmaild.rc stop should also be executed at system shutdown, but is not strictly necessary.

Tweak the web server for MSIE

The MSIE browser has a number of bugs in its HTTP/1.1 implementation, at least as of MSIE 4.x and 5.x. You must configure your web server to use HTTP/1.0 when talking to any MSIE browser (at least until MSIE gets fixed). The problem has to do with downloading attachments. Apparently, MSIE forgets how MIME works, when it uses HTTP/1.1. For the Apache server, insert the following directive in httpd.conf:

BrowserMatch "MSIE" nokeepalive downgrade-1.0 force-response-1.0

Recent versions of Apache already have a similar directive for a specific version of MSIE, MSIE 4.0b2. Just replace it with a browsermatch for any MSIE version.

Load the login screen

Specify the URL to the sqwebmail binary to display the login page. Try to log in to a test account. Review the rest of this configuration file in order to enable optional features that you want to use.

IMAP and Unicode

The option --disable-utf7-folder-encoding removes some code from SqWebMail that's not needed if the mail accounts are not accessible via IMAP. IMAP encodes names of folders that contain non-ASCII characters using a scheme called "modified-UTF7". Currently, the only known IMAP server compatible with SqWebMail is Courier-IMAP.

Modified-UTF7 support involves some overhead, so this option can be used to disable modified-UTF7. If there isn't going to be any IMAP access to the same mail accounts, there's no need to include all this baggage.

There are a few IMAP clients that do not use modified UTF7 to encode folder names. --disable-utf7-folder-encoding should be used if that is the case. It is not possible to support both UTF7 and non-UTF7 clients at the same time.

The additional overhead in SqWebMail consists of translation tables that map the local character set to Unicode (from which modified UTF-7 is derived). This is what happens unless the --disable-utf7-folder-encoding option is used. The configure script takes the character set used for the HTML templates, and loads the Unicode mappings just for that character set. By default, SqWebMail is distributed with a single set of HTML templates that use the iso-8859-1 character set. If you are installing a modified derivative that includes additional templates, the configure will pick up any additional character sets used by those templates. The list of all the available character sets can be found in the file unicode/charsetlist.txt.

You may observe that all the available character sets will be compiled. Rest assured that only the required character sets will be included in the final SqWebMail executable.

IMPORTANT: for UTF7 encoding to work correctly, it is necessary to set the same identical character set in all applications involved: the IMAP client, and SqWebMail. For SqWebMail, it means that the CHARSET file in the HTML template directory must be initialized to set the correct character set.

The option --enable-unicode can be used to explicitly specify which character set tables to include, overriding the default selected by the configure. Sometimes this is useful when there are alternative encodings for the same base character set, like KOI8-R and IBM866. The option "--enable-unicode=koi8-r,ibm866" - when used with HTML templates for the koi8-r character set - allows SqWebMail to display ibm866-encoded E-mail using the koi8-r character set (and vice versa). Note, for this to work you will need to install a set of KOI8-R HTML templates. In a pinch, you can simply edit sqwebmail/html/en/CHARSET.

NOTE: the utf-8 character set MUST be specified if GnuPG 1.0.5 (or later) is used. The configure script defaults to enabling unicode support and adding the utf-8 character set if the script finds that GnuPG 1.0.5 (or later).

Spell checking

SqWebMail can use either the ispell or the aspell package for spell checking messages. Install ispell or aspell before installing SqWebMail.

NOTE: SqWebMail assumes that the spell checking dictionary is called "english". Some systems use a different name for the default spell checking dictionary. To change the name of the spell checking dictionary used by SqWebMail, put the name of the dictionary into the file /usr/lib/sqwebmail/share/sqwebmail/html/en-us/ISPELLDICT.

PAM authentication

SqWebMail uses the "webmail" service with the Courier authentication library. When the optional groupware calendaring mode is enabled, SqWebMail also uses the "calendar" service. You will have to take additional, site-specific, steps in order to configure your PAM library for the "webmail" and "calendar" PAM services. The specific details regarding your PAM configuration differs from system to system, and you should consult your own documentation.

See the Courier authentication library documentation for more PAM-related information.

HINT: try to look at how other PAM services are set up, and duplicate their configuration for the webmail and calendar services. A good example to follow would be the ppp service, if it exists.

Password changes

After installing SqWebMail be sure to test that the login password can be changed through SqWebMail. Be sure to change the password a couple of times, logging out and back in each time.

If you do not want to use the password change function you can also remove the sqwebpasswd program. This is a helper program, installed with the set-groupid bit set, that relays the password change request to the authentication daemon, through the filesystem socket that is not globally accessible. The password change request consists of the account name, the old password, and the new password. The password change request is validated by the authentication daemon, and the old password must match the existing password on the account, before the password change goes through. This set-groupid helper program is safe to use.

Runtime configuration

There are some options which can be used to change sqwebmail's behaviour on individual accounts, or globally, using the "Account Options" feature in the Courier Authentication library. The individual account's setting takes precedence over the DEFAULTOPTIONS settings in the authdaemonrc configuration, so for example if you want to disable webmail access for most accounts but enable it for a select few, you can set DEFAULTOPTIONS="disablewebmail=1" in the authdaemonrc configuration file, and add the option disablewebmail=0 to individual accounts. See the section "Account options" in README_authlib.html in the courier-authlib package for more information on setting the following account options:

disablewebmail - if set to a non-zero value, this account will not be permitted to login to webmail (e.g. because the user is only allowed to use POP3 or IMAP)

wbnochangingfrom - if set to a non-zero value, SqWebMail will not allow the From: header to be changed, it will always have its default value.

wbnochangepass - if set to a non-zero value, SqWebMail will not allow passwords to be changed. See "Password changes", above, for more information.

wbusexsender - if set to a non-zero value, SqWebMail will attach an X-Sender: header to all outgoing messages. This can be used in the event you would like to be able to modify the From: header, yet also be able to track sent mail to the original account. Although your mail server should records the id of the sending user in the headers of outgoing messages, this is not possible when you have many virtual accounts that share the same system userid.

wbnoimages - if set to a non-zero value then no images or icons will be used. The generated interface will be a text-only interface.

wbnodsn - set to a non-zero value then the option to request delivery confirmation receipts will not be shown. Delivery confirmation receipts require the local mail server to support RFC 1894 delivery status notifications, and some mail servers do not implement DSNs. Qmail does not implement DSNs, so this file is created by default since most SqWebMail installations use Qmail. Remove this file if the local mail server is not Qmail, and it implements DSNs.

In addition, there's some global configuration that can be done after installation. The following presumes that SqWebMail's configuration files are installed in /usr/lib/sqwebmail (the default).

/usr/lib/sqwebmail/etc/hostname - when SqWebMail is installed with a basic configuration for a single domain, SqWebMail sets the domain in the return address for outgoing messages to the defined system hostname. If this file exists it will be used instead of the defined system hostname.

/usr/lib/sqwebmail/etc/autoresponsesquota - the systemwide quota on autoreplies, if autoreplies and mail filtering are enabled. This file contains one line: "Cnnn" or "Snnn" (or both strings, on the same line). Cnnn: allow up to #nnn autoreplies to be created. Snnn: allow up to #nnn bytes as the total size of all autoreplies, combined. If both Cnnn and Snnn are specified, both quotas apply. If this file does not exist, there is no limit on autoreplies. This quota setting applies systemwide. To override the quota setting for a particular Maildir, create the autoresponsesquota file in that Maildir (which takes precedence).

/usr/lib/sqwebmail/share/sqwebmail/sendit.sh is a shell script that's called to actually mail a message. It can be customized to do something like rewriting some of the headers, or adding the client's IP address to the headers (sqwebmail does not do that by default).

/usr/lib/sqwebmail/etc/logindomainlist - if this file exists, it can be used in a vast number of ways to fine tune the user login experience. See README.logindomainlist.html for more information.

/usr/lib/sqwebmail/share/sqwebmail/html/LANG/footer - if this file exists, its contents will be appended to the end of every sent message. LANG is the language code here, there can be a separate footer per installed language.

/usr/lib/sqwebmail/share/sqwebmail/html/LANG/TIMEZONELIST - a list of alternative timezones. By default all dates and times are shown in the server's default timezone, and the dropdown list on the login screen can be used to select an alternative timezone. SqWebMail comes with a default alternative timezone list that lists only a small number of timezones. Additional timezones can be entered into this file to be shown on the login screen.

Account Initialization Hook

If there is a file or a symbolic link in the maildir called "loginexec", and if it is executable, then the executable file will be invoked after a succesful login. If the program terminates with an exit code of 0, the "loginexec" file (or a symbolic link) will be removed.

Adjusting session timeouts

A login session is automatically logged out after certain period of inactivity. The timeout period defaults to 20 minutes, and is set by the --enable-softtimeout option to the configure script. It is also possible to adjust this value by setting the SQWEBMAIL_TIMEOUTSOFT environment variable. For example, with Apache, by adding the following to httpd.conf:

SetEnv SQWEBMAIL_TIMEOUTSOFT 3600

There is also a hard timeout, which logs out a session no matter what. The default of two hours is changed with the --enable-hardtimeout option to the configure script, and the SQWEBMAIL_TIMEOUTHARD environment variable.

WARNING:

The hard timeout interval is used to calculate the maintenance of the login cache (if that option is selected). This factor is used in the cleancache.pl cleanup script, and changes to this value must be coordinated appropriately. It is not possible to use different hard timeout values with the same login cache (in different virtual domains, as described in the next session). Leisurely tinkering with this environment variable is STRONGLY DISCOURAGED, it's very easy to screw up the whole system. You've been warned.

If you adjust the hard timeout, you must simultaneously delete your current login cache directory, and adjust $timeouthard in the installed cleancache.pl script.

Domain-based templates

The default set of templates for the dynamically generated HTML is installed in /usr/lib/sqwebmail/share/sqwebmail/html. When the same server is used to provide webmail access for multiple domains it is possible to specify a different set of HTML templates for each domain.

This functionality is not directly implemented in SqWebMail, simply because there is no standard way to specify this. Instead, this is something that will need some minor work set up.

Domain-based templates are implemented by making the web server set the environment variables SQWEBMAIL_TEMPLATEDIR prior to running the sqwebmail binary. The contents of this environment variable override the default location of /usr/lib/sqwebmail/share/sqwebmail/html. By having the web server initialize this variable based on the domain name it is possible to present different templates, based on the domain name used.

To do this, make copies of the HTML template directory, /usr/lib/sqwebmail/share/sqwebmail/html. Then, configure the web server to initialize SQWEBMAIL_TEMPLATEDIR appropriately. For example, with Apache:

  <VirtualHost a.b.c.d>
    ServerName webmail.example.com
    [...]
    SetEnv SQWEBMAIL_TEMPLATEDIR /usr/lib/sqwebmail/share/sqwebmail/webmail.example.com
    [...]
  </VirtualHost>
The possibilities are endless.

Name-based templates

In versions of sqwebmail greater than sqwebmail-3.5.3.20030629 it is possible to display two or more templates from the same CGI binary WITHOUT setting up multiple domain names.

For example, with Name-based templates an sqwebmail administrator can set up sqwebmail to display a template in the /usr/lib/sqwebmail/share/sqwebmail/html directory when sqwebmail is called from the URL: http://www.foo.com/cgi-bin/sqwebmail

And display a different template in the /usr/lib/sqwebmail/share/sqwebmail/alternate-html directory when sqwebmail is called from the URL: http://www.foo.com/cgi-bin/sqwebmail-alt-template

This is made possible by a little web server magic (explained below in the section entitled "Apache Name-based template configuration example") and the setting of TWO sqwebmail environment variables:

SQWEBMAIL_TEMPLATEDIR SQWEBMAIL_IMAGEURL

You should recognize the SQWEBMAIL_TEMPLATEDIR environment variable from the section above on Domain-based templates. If you haven't read that section yet, please do so now.

The SQWEBMAIL_IMAGEURL environment variable is new in versions of sqwebmail greater than sqwebmail-3.5.3.20030629. It allows us to set, at run time, the image URL, or the root URL, in which to look for our template's images. This image URL is then automatically inserted into the current template anytime a conditional image tag or an IMAGEURL tag is encountered.

This is an example of a conditional image tag:

[#@image.gif, ... @text@#]

The conditional image tag is replaced at template processing time with an HTML <img src="..."> tag if (hence the word "conditional") sqwebmail is set up to display images.

This is an example of an IMAGEURL tag:

[#IMAGEURL#]

The IMAGEURL tag is replaced at template processing time with the contents of the SQWEBMAIL_IMAGEURL environment variable, if set, and otherwise with the value of the --with-imageurl configure option, which defaults to "/webmail".

Apache Name-based template configuration example

Let's take a look at a simple Apache Name-based sqwebmail template configuration example:

  
  # Sqwebmail Alternate Template URL
  ScriptAlias /cgi-bin/sqwebmail-alt-template "/usr/local/apache/cgi-bin/sqwebmail"

  <Location /cgi-bin/sqwebmail-alt-template>
      Setenv SQWEBMAIL_TEMPLATEDIR "/usr/lib/sqwebmail/share/sqwebmail/alternate-template"
      Setenv SQWEBMAIL_IMAGEURL "/alternate-webmail"
      [...]
  </Location>
      

The above should allow your users to run sqwebmail with the template in /usr/lib/sqwebmail/share/sqwebmail/alternate-template and an image URL of /alternate-webmail, simply by calling sqwebmail from the following URL:

http://www.yourdomain.com/cgi-bin/sqwebmail-alt-template

The original sqwebmail templates would then still be available from this URL:

http://www.yourdomain.com/cgi-bin/sqwebmail

Using Apache's <Location> directive we can utilize a virtually unlimited number of templates without setting up a single virtual domain.

Shared folders

SqWebMail supports shared folders. The SqWebMail distribution includes an enhanced maildirmake command that created shared folders.

The maildirmake command will be installed in /usr/lib/sqwebmail/libexec/sqwebmail by default, and the manual page will be installed in /usr/lib/sqwebmail/man by default.

See the manual page for more information on how to set up shared folders.

LDAP address books

SqWebMail can import E-mail addresses from public LDAP address books into an individual address book. A default systemwide list of accessible LDAP address books is defined for everyone, and individuals can configure additional LDAP address books for themselves.

OpenLDAP runtime libraries and tools are required to be installed in order to search LDAP address books. It is not necessary to have OpenLDAP development libraries installed. SqWebMail simply runs the ldapsearch tool to query LDAP address books, and parses the results.

The file /usr/lib/sqwebmail/etc/ldapaddressbook should contain a default systemwide list of accessible address book. A default file will be installed, listing some common Internet address books. Each line in this file contains the following information:

name<tab>host<tab>port<tab>suffix<tab>binddn<tab>bindpw

<tab> is a single ASCII TAB character.

The file /usr/lib/sqwebmail/share/sqwebmail/ldapsearch is a wrapper shell script that calls the ldapsearch tool. The configuration script attempts to find the location of where OpenLDAP tools are installed. The path to ldapsearch in this shells script should be verified and fixed, if necessary. The default shell script adds some additional options to ldapsearch to limit the search time to sixty seconds, and to return a maximum of twenty entries from the address book.

Mail Filtering

Mail filtering is an optional feature. Mail filtering allows installation of rules that either automatically deliver incoming messages to specific folders, forward it, or reject it, based on the contents of the message's header or body. A simple autoreply function is also available. Mail filtering requires that the maildrop mail filter must be installed as the local mail delivery agent. Mail filtering requires maildrop version 1.3.4, or higher. SqWebMail will generate a filtering recipe for maildrop to use when delivering mail. Maildrop's mail filtering language is very powerful, and SqWebMail can reasonably use only a fraction of the mail filtering language, but enough functionality is supported for the majority if mail filtering needs.

For information on installing and activating mail filtering, see the file maildir/README.maildirfilter.html.

Autoreplies

The mail filtering option can also be used to set up autoreplies. Autoreplies are prepared in advance on a separate screen. By default there is no limit on the number of the size of created autoreplies, therefore it is recommended that a quota be set up on the autoreplies (see "Runtime Configuration").

Autoreplies can include any valid MIME content (MIME content other than plain text can be uploaded). The following special procedure needs to be used to prepare multipart autoreply content, such as text and html alternatives of the same message:

Assign a filename extension to the message/rfc822 MIME content. For example, edit your mime.types file, find the message/rfc822 MIME type (append one if it's not in mime.types), and make sure that it has at least one filename extension, such as "msg".

Prepare the multipart MIME autoreply. The most convenient way is to prepare a normal E-mail message using a conventional E-mail client. Save the RFC822-formatted message in a file with a ".msg" extension, and upload it on the autoreply screen.

SqWebMail handles uploaded message/rfc822 content by removing all headers except the MIME headers, leaving the MIME content type header, and the actual MIME content.

Calendaring

This release of SqWebMail contains a beta implementation of basic calendaring, that can be optionally enabled. For more information, see the file pcp/README.html. SqWebMail's calendaring implementation is designed to be used on a private mail server. It is not suitable for use on public webmail servers. See the README file for additional information.

Encryption

SqWebMail can be set up to encrypt and decrypt mail using GnuPG. For more information on setting up and using encryption, read the file gpglib/README.html in the source distribution.

FAQ: Problems with downloading attachments with Internet Explorer versions 4 and 5

Certain versions of Microsoft Internet Explorer have a bug in HTTP/1.1 protocol implementation that results in MSIE reporting random weird errors when downloading attachments.

Here's how to tweak Apache to work around this particular bug. Add the following directive to Apache's httpd.conf forces the HTTP/1.0 protocol response for Internet Explorer clients:

BrowserMatch "MSIE [45]" nokeepalive downgrade-1.0 force-response-1.0