Debian 10 has now fully switched to Systemd which means that the traditional commands to halt or reboot a system like 'shutdown -h now' or 'reboot' will not work anymore. First of all, run the command as root user. Prepend the sudo command to become root user if needed. Here are their systemd equivalents which ... Read more
If all your visitors shall access your website with a URL like www.domain.com and not without www, use the following apache rewrite rule for redirecting them. RewriteEngine On RewriteCond %{HTTP_HOST} !^www RewriteRule (.*) http://www.%{HTTP_HOST}$1 [L,R] The apache rewrite rule can be added in a .htaccess file in the website root directory or if you use ... Read more
When a server has more than one IP address, then postfix will use all IP addresses randomly to send out emails. This can cause your emails to be listed as SPAM on other servers because the sending IP does not match the reverse IP of the server hostname. The solution is to bind postfix to ... Read more
If you use postfix and / or amavisd-new on the mail server, you can use the following recipes to block emails with executable (exe, bat, scr) attachments. Block the attachments with a postfix header filter In ISPConfig, click on "Email in the upper menu, then on "Content filter" in the left menu and click on ... Read more
Sometimes you might have to work with the Spamassin Bayes Token database. This is the database that is used by the SpamAssassin Self Learning (Bayesian) Classifier to store the ham and spam tokens. This tutorial will show you how to make a backup of that database. E.g. when you want to move it to a ... Read more
NOTE: This post is about ISPConfig 3.0 and not 3.1 and newer. ISPConfig 3.1 and newer has DKIM support builtin, you can simply enable DKIM in ISPConfig 3.1 GUI now for the mail domain. DKIM is a system to verify the sender and integrity of emails. ISPConfig 3 uses amavisd-new as content filter for spam ... Read more
You get the following error message while installing a .deb package on Debian or Ubuntu or while installing Updates? E: Could not get lock /var/lib/dpkg/lock - open (11: Resource temporarily unavailable) E: Unable to lock the administration directory (/var/lib/dpkg/), is another process using it? This error means that there is already an apt process running or ... Read more
Ubuntu's Unity graphical shell is pretty good when it comes to customization. Just think of a change, and you'll find that it can be done - for what it's worth, you can also move the Unity Launcher from side to bottom starting Ubuntu 16.04. However, there are certain things that are difficult to achieve in ... Read more
While shutting down (or other similar operations like restarting and logging-out) aren't difficult to launch in Ubuntu (you can find them in the Gear system menu on top-right corner of your desktop), some users - for whatever reason - may want to have a Unity Launcher icon for them. In this tutorial, we will explain ... Read more
Sometimes, it helps save precious time if you can quickly access recently-opened files. In Ubuntu, the file explorer that ships with the distribution does offer this functionality, but you may need to take some steps before the option shows up. For example, the following screenshot shows that the option isn't enabled in my case: In ... Read more