Install Squirrel Mail on Ubuntu 10.04 server

To install the SquirrelMail webmail client, run

aptitude install squirrelmail

Then create the following symlink...

ln -s /usr/share/squirrelmail/ /var/www/webmail

... and configure SquirrelMail:

squirrelmail-configure

We must tell SquirrelMail that we are using Courier-IMAP/-POP3:

SquirrelMail Configuration : Read: config.php (1.4.0)
---------------------------------------------------------
Main Menu --
1. Organization Preferences
2. Server Settings
3. Folder Defaults
4. General Options
5. Themes
6. Address Books
7. Message of the Day (MOTD)
8. Plugins
9. Database
10. Languages

D. Set pre-defined settings for specific IMAP servers

C Turn color on
S Save data
Q Quit

Command >> <-- D


SquirrelMail Configuration : Read: config.php
---------------------------------------------------------
While we have been building SquirrelMail, we have discovered some
preferences that work better with some servers that don't work so
well with others. If you select your IMAP server, this option will
set some pre-defined settings for that server.

Please note that you will still need to go through and make sure
everything is correct. This does not change everything. There are
only a few settings that this will change.

Please select your IMAP server:
bincimap = Binc IMAP server
courier = Courier IMAP server
cyrus = Cyrus IMAP server
dovecot = Dovecot Secure IMAP server
exchange = Microsoft Exchange IMAP server
hmailserver = hMailServer
macosx = Mac OS X Mailserver
mercury32 = Mercury/32
uw = University of Washington's IMAP server
gmail = IMAP access to Google mail (Gmail) accounts

quit = Do not change anything
Command >> <-- courier


SquirrelMail Configuration : Read: config.php
---------------------------------------------------------
While we have been building SquirrelMail, we have discovered some
preferences that work better with some servers that don't work so
well with others. If you select your IMAP server, this option will
set some pre-defined settings for that server.

Please note that you will still need to go through and make sure
everything is correct. This does not change everything. There are
only a few settings that this will change.

Please select your IMAP server:
bincimap = Binc IMAP server
courier = Courier IMAP server
cyrus = Cyrus IMAP server
dovecot = Dovecot Secure IMAP server
exchange = Microsoft Exchange IMAP server
hmailserver = hMailServer
macosx = Mac OS X Mailserver
mercury32 = Mercury/32
uw = University of Washington's IMAP server

quit = Do not change anything
Command >> courier

imap_server_type = courier
default_folder_prefix = INBOX.
trash_folder = Trash
sent_folder = Sent
draft_folder = Drafts
show_prefix_option = false
default_sub_of_inbox = false
show_contain_subfolders_option = false
optional_delimiter = .
delete_folder = true

Press any key to continue... <-- ENTER


SquirrelMail Configuration : Read: config.php (1.4.0)
---------------------------------------------------------
Main Menu --
1. Organization Preferences
2. Server Settings
3. Folder Defaults
4. General Options
5. Themes
6. Address Books
7. Message of the Day (MOTD)
8. Plugins
9. Database
10. Languages

D. Set pre-defined settings for specific IMAP servers

C Turn color on
S Save data
Q Quit

Command >> <-- S


SquirrelMail Configuration : Read: config.php (1.4.0)
---------------------------------------------------------
Main Menu --
1. Organization Preferences
2. Server Settings
3. Folder Defaults
4. General Options
5. Themes
6. Address Books
7. Message of the Day (MOTD)
8. Plugins
9. Database
10. Languages

D. Set pre-defined settings for specific IMAP servers

C Turn color on
S Save data
Q Quit

Command >> S

Data saved in config.php
Press enter to continue... <-- ENTER


SquirrelMail Configuration : Read: config.php (1.4.0)
---------------------------------------------------------
Main Menu --
1. Organization Preferences
2. Server Settings
3. Folder Defaults
4. General Options
5. Themes
6. Address Books
7. Message of the Day (MOTD)
8. Plugins
9. Database
10. Languages

D. Set pre-defined settings for specific IMAP servers

C Turn color on
S Save data
Q Quit

Command >> <-- Q

Afterwards you can access SquirrelMail under http://server1.example.com/webmail or http://192.168.0.100/webmail: