How to compress email attachments automatically in Mozilla Thunderbird

There is a handy Thunderbird extension named "Auto zip" available that compresses email attachments as .zip files automatically, So you dont have to compress the files manually anymore before you attach them to the email.

Thunderbird extension download:

https://addons.mozilla.org/en/thunderbird/addon/4003

Sadly, the official version of the plugin works only for thunderbird 2. But a few users offer already patched versions for Thunderbird 3 (see links in the comments). Please be aware that using such a patched version has the risk that it might contain malicious code.)

https://addons.mozilla.org/de/thunderbird/reviews/display/4003

How to block access to a server by IP address on Linux

Sometimes you might want to block connects to your server by IP address. E.g. when someone tries to attack your system. This can be done in several different ways, e.g. with iptables (firewall) rules or by setting up a reject route. Using iptables sometimes causes conflicts with installed firewalls so that I will use the route command here. The command is:

/sbin/route add -host 192.168.0.123 reject

Replace 192.168.0.123 with the IP address that you want to block and execute the command as root user on the shell.

How to enable the new multisite feature in WordPress 3.0

If you recently updated to or installed WordPress 3.0, you might wonder where the menu for Multisite feature is. By default, these new functions are disabled after a WordPress update, to enable them, edit the file wp-config.php and add the line

define(‘WP_ALLOW_MULTISITE’, true);

On your next login, you will see a new menu labeled "Super Admin" which contains the functions to add new sites to wordpress.

How to build a pure-ftpd Debian package for OpenVZ virtual machines (without capabilities enabled)

The pure-ftpd package that comes with Debian 5.0 (Lenny) does not start in a OpenVZ virtual machine as it is compiled with "capabilities". This tutorial describes the steps to build a pure-ftpd Debian package with capabilities disabled:

Make a temporary directory

mkdir /usr/src/pure-ftpd
cd /usr/src/pure-ftpd

Download the source package for pure-ftpd

apt-get source pure-ftpd
apt-get build-dep pure-ftpd

Edit the rules file and add the switch "--without-capabilities"

cd pure-ftpd-1.0.21/debian
nano rules

Change the line:

optflags=--with-everything --with-largefile --with-pam --with-privsep --with-tls

to (one Line!):

optflags=--with-everything --with-largefile --with-pam --with-privsep --with-tls --without-capabilities

Build the Debian (.deb) package

cd ..
dpkg-buildpackage -uc -b

and install it

cd ..
dpkg -i pure-ftpd-common_1.0.21-11.4_all.deb pure-ftpd-mysql_1.0.21-11.4_i386.deb
/etc/init.d/pure-ftpd-mysql restart

To prevent that apt overwrites these manually compiled packages with the default packages from the Debian repositorys, execute these commands:

echo 'pure-ftpd-common hold' | dpkg --set-selections
echo 'pure-ftpd-mysql hold' | dpkg --set-selections

This tutorial is based on the german tutorial from planet_fox

How to update Spamassassin on ISPConfig 2

The spamassassin installation on a ISPConfig 2 server is normally updated together with ISPConfig. Here are the steps iIf you want to update spamassassin manually without updating ISPConfig 2:

Download the latest Spamassassin sources and unpack the tar.gz file

cd /tmp
wget http://ftp.fernuni-hagen.de/ftp-dir/pub/mirrors/\
www.apache.org/spamassassin/source/Mail-SpamAssassin-3.3.1.tar.gz
tar xfz Mail-SpamAssassin-3.3.1.tar.gz

Configure, make and install spamassassin

cd Mail-SpamAssassin-3.3.1
perl Makefile.PL PREFIX=/home/admispconfig/ispconfig/tools/\
spamassassin/usr SYSCONFDIR=/home/admispconfig/ispconfig/\
tools/spamassassin/etc
make
make install

Cleanup

cd ..
rm -f Mail-SpamAssassin-3.3.1.tar.gz
rm -rf Mail-SpamAssassin-3.3.1

How to enable port 587 (submission) in postfix

Some internet access providers have port 25 disabled in their routers to prevent spam. If you run your own mailserver in a datacenter, you might have to enable the submission port (587) in postfix to be able to send emails from your local email client to your own mailserver.

To enable port 587, edit the file /etc/postfix/master.cf

vi /etc/postfix/master.cf

and remove the # in front of the line:

#submission inet n - n - - smtpd

so that it looks like this:

submission inet n - n - - smtpd

and restart postfix:

/etc/init.d/postfix restart

NiceToHave tool for monitoring from the command line with Saidar

With Saidar you can display and view all your system statistics.

For an installation in Ubuntu or Debian you can install this with following command:

sudo apt-get install saidar

After having installed it, you can type in the command saidar:

saidar

Now you see in the following screen a complete view of your CPU, processes, load, memory, swap network I/O and disks I/O along with their free space.

The following options are supported:

-d    (Wait DELAY seconds between updates (default 3))

-v   (Prints the version number)

-h   (Display help and exits)

That's it! Thanks to Planetfox for this tipp.

How to solve the ClamAV error “This version of the ClamAV engine is outdated” on Debian 5.0 (Lenny)

As of today, all ClamAV 0.94 or older installs will stop working. The Debian project has not released updates for their current stable release (5.0) yet to solve this, but there is a workaround. The Debain volatile project provides newer clamav versions. The installation steps to install ClamAV 0.95.3 on Debian lenny are:

1) Add the debian volatile repository to the sources list:

echo "deb http://volatile.debian.org/debian-volatile lenny/volatile main contrib non-free" >> /etc/apt/sources.list

2) Update the sources and install the new clamav package:

apt-get update
apt-get install clamav
apt-get -u upgrade

3) If you use amavisd-new (e.g. if you use a ISPConfig 3 server) then restart amavisd:

/etc/init.d/amavis restart

Apache webserver: redirect requests for domain.com to www.domain.com

Many webmasters want to redirect users that access their websites with "domain.tld" automatically to "www.domain.tld". If you use the Apache web server, you can do this by using Apache rewrite rules.

Add a .htaccess file with the following content in the root directory of the website:

RewriteEngine On
RewriteCond %{HTTP_HOST} !^www\.domain\.com
RewriteRule (.*) http://www.domain.com/$1 [L,R=301]

If you use ISPConfig as hosting control panel, you can add these rules also in the Apache directives field of the website instead of a .htaccess file

Get a list of all virtual hosts which are defined in all apache configuration files

Have you ever searched where the virtual host of a website is defined in the apache config files? There is a handy option of the apache2ctl script which might help then. When you run the command:

apache2ctl -S

on the shell, you will get a list of all virtual hosts and default servers incl. the line number where it is defined. Example:

~# apache2ctl -S
VirtualHost configuration:
wildcard NameVirtualHosts and _default_ servers:
*:8080                 is a NameVirtualHost
default server ispconfig.local (/etc/apache2/sites-enabled/000-ispconfig.vhost:10)
port 8080 namevhost ispconfig.local (/etc/apache2/sites-enabled/000-ispconfig.vhost:10)
*:8081                 is a NameVirtualHost
default server ispconfig.local (/etc/apache2/sites-enabled/000-apps.vhost:10)
port 8081 namevhost ispconfig.local (/etc/apache2/sites-enabled/000-apps.vhost:10)
*:80                   is a NameVirtualHost
default server ispconfig.local (/etc/apache2/sites-enabled/000-default:1)
port 80 namevhost ispconfig.local (/etc/apache2/sites-enabled/000-default:1)
port 80 namevhost example.com (/etc/apache2/sites-enabled/example.com.vhost:7)
Syntax OK

Thanks to Planetfox for this tipp.