Installing Webmin and SARG
yum install sarg

yum install sarg
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:
How to add a user to the sudoers list? Beleive it or not, this is a fairly common question and in all reality the answer is quite simple. Adding a user to the sudoers list on a fully installed Linux system such as Debian is only possible via the command visudo. Users in the sudoers list are allowed the privileges to run commands and open files as the root user. In the following quick tutorial, we will show you how adding a new sudoer is quickly done.
How to add a user to the sudoers list:
root ALL=(ALL) ALL
user ALL=(ALL) ALL
That's it, your new user now has root privileges!
Example Sudoers Screenshot:
The growth of the internet, and e-mail in particular, has given rise to numerous types of encryption software for the secure transmission of information. There are various reasons for wanting to encrypt your e-mail today:
Encryption on the internet is not unlike your typical lock and key combination. What you'll need to do is choose the lock, in the form of encryption platform, and then generate a key to lock (encrypt) or unlock (decrypt) your data.
There are various encryption platforms. Some popular standards include:
Because encryption ought to be tightly integrated with your e-mail client, the standard you end up using is probably going to be determined by what works with your e-mail client of choice. For example, Microsoft Outlook comes with TDEA encryption, Apple's Mail supports X.509 encryption, and there is a GPG add-on for Firefox that works with Google's GMail.
To get started with encryption, you need to create an encryption key pair, which is like a digital signature and pass code. Your e-mail client or stand-alone encryption software might be able to create these keys for you or you may be directed to the web site of a certificate authority such as Thawte or Verisign to create and store your key.
Enter your full name, your e-mail address, and create a pass phrase that will ensure that only you can use your key. Your pass phrase should be fairly long and complicated - you shouldn't use names, dates, addresses, or anything else that can be easily guessed at. One simple method is to use mondegreens; you know, those misinterpreted words you used to sing along with, until you learn what the real lyrics really are and become terribly embarrassed. For example, Jimi Hendrix's "'scuse me, while I kiss this guy."
Certificate authorities create a key pair of both a private and a public key for you. The only people who should have access to your private key are you and the certificate authority; this key is what allows you to encrypt files and decrypt files meant just for you. The public key is freely distributed to anyone you correspond with; it allows other people to check your digital signature to confirm that you are the actual author, and it allows them to encrypt files and messages that only you can decrypt. Depending on the encryption standard you are using, you may have to send people your public key by attaching a file, or it may be automatically downloaded from the certificate authority's public key server.
The two most common functions of encryption software are Signing and Encrypting. Signing an e-mail lets anyone who has access to your public key decrypt the message, and serves to confirm that you are the original author. Signing is useful in situations where unsavory characters may be sending out fraudulent information in your name and you need people to know what information is really coming from you. Encrypting scrambles plain text or file attachments and only allows the intended recipient to access them. Encrypted files and messages are also signed as a matter of course, so the recipient can also confirm that the message they are decoding did actually come from you.
As computers get more powerful, it becomes easier to crack encryption. In fact, one of the very first digital computers ever created, Colossus, was used to decrypt German codes during World War II. Typically as code breakers get more powerful, encryption systems just use longer and longer codes to slow down brute-force attempts to guess them: right now most desktop encryption software offers up to 4,096-bit encryption.
An entirely new system of encryption is being developed that takes advantage of the principles of quantum mechanics: quantum encryption creates an entangled key pair of qubits that is shared among two parties. These entangled qubits allow the two parties to share information securely, and - due to the peculiar role observation plays in quantum mechanics - also alerts them if anyone is attempting to eavesdrop on their secure channel. Quantum cryptography is already running on experimental military and university communication networks, and if the example of the World War II code-breaking machines is any indication, it's only a matter of time until the technology trickles down to consumers.