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
Have you recently upgraded your Ubuntu machine from version 16.10 to 17.04? Are you missing the "Open New Terminal" option that used to be there in the right-click menu of the terminal icon in the launcher? If your answer to both these questions is yes, then you'll be glad to know that there exists a ... Read more
If you are an Ubuntu user, you might have observed the dialog box that gets displayed when you quickly press and leave the power button. The dialog box contains icons to Lock, Suspend, Restart, and Shutdown the system. Have you ever found yourself wondering how this box can be launched from the command line? Well, ... Read more
If you are one of those who prefer using keyboard over mouse wherever and whenever possible, I am sure you must be aware of what Alt+Tab does. For starters, this key combination lets you switch between windows of the currently open/active applications. While Alt+Tab is good for making a switch across applications, it's not an ... Read more