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Category: Open-Source

LAMP-Securing Your Web Server With SSL

LAMP-Securing Your Web Server With SSL

Hello and welcome! In my previous post on LAMP web server, I discussed about its installation and configuration inside CentOS environment. Today, I’m writing on how to setup SSL certificate in our website and other security related configurations as well. Installing SSL Certificate First of all, let’s install mod_ssl package from MOD Security. It’s done in CentOS as follows: Then, let’s create a directory where we’ll keep our SSL certificates. Now, let’s generate self-signed certificate for our web server. Here, openssl is…

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Blocking Mails Based on Subject in Zimbra

Blocking Mails Based on Subject in Zimbra

Welcome back! In this post, let’s talk about tightening our Antispam or Spamassassin in Zimbra. In real-time, there may be a serious reason for filtering and blocking mails based on subject that contain certain structures or words. Here are the steps to achieve this objective in Zimbra 8.5 and later. 1) Create a policy file inside /opt/zimbra/data/spamassassin/rules/ as root user e.g. Here, SUB_ATTACHMENT is a rule that filters the mail header based on the regular expression match of Subject. The describe…

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Enable Authentication In Zimbra CBPolicyd Webui

Enable Authentication In Zimbra CBPolicyd Webui

Hello there! In this post, I’m going to write about how to enable authentication in Zimbra CBPolicyd Webui. If you use Zimbra but haven’t yet used CBPolicyd, I recommend you to see me previous post where I discussed about installation and use of CBPolicyd for managing mail related rules or restrictions in Zimbra. Until now, we don’t have any kind of authentication mechanism to protect our CBPolicyd’s web panel. So, let’s go ahead and setup an authentication method for our…

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Restricting Certain Users from Sending/Receiving External Mails in Zimbra

Restricting Certain Users from Sending/Receiving External Mails in Zimbra

Hello! In this post, I’m going to talk about how to configure a Zimbra server to restrict certain users from sending or receiving mails from external domains. In order to achieve this objective, Zimbra provides two alternatives: one using CBPolicyd (web based) and another using MTA restrictions (cli based). Here I’m covering both methods. First, let’s have a look at CBPolicyd. Note: The methods mentioned here are tested successfully in ZCS 8.5 and ZCS 8.6. I cannot confirm its validity…

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Zimbra Distribution Lists Disappearing Issue

Zimbra Distribution Lists Disappearing Issue

Welcome! In this post, I’m once again going to discuss about Zimbra Collaboration Suite. This is about an incident that I recently came across, in which some of the mail distribution lists of one of our clients got automatically removed from the system. On doing some research, I learned that this type of issue was faced in past versions of ZCS, and had been resolved long ago. However, in this case, our client had the latest ZCS version of the…

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LAMP- Installation and Configuration in CentOS 7

LAMP- Installation and Configuration in CentOS 7

Hello! Today, let’s install and configure a web server (Linux + Apache + MySQL + PHP = LAMP) in CentOS7 platform. I think this subject can be very helpful to web developers, students and system administrators. Without any adieu, let’s get started with the installation and configuration. Installation of CentOS 7 I’ve already written blogs on installation and initial configuration of CentOS 7 operating system in my previous posts. You can refer to these blog posts: Creating VM in VMware…

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Backup/Restore Zimbra LDAP for DR

Backup/Restore Zimbra LDAP for DR

Overview In this post, I’m going to cover the topic on how to backup and restore LDAP database and config in case of disaster. If you’re a Zimbra administrator, this is a must have knowledge. This can be useful for anyone with an interest in system administration and mail servers. The reason I’m writing this blog is to help others in quickly recovering from a disaster, based on my personal experiences. I understand how it feels to have your system damaged or…

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Setup Zimbra Mail Server-Post Installation

Setup Zimbra Mail Server-Post Installation

Welcome back! If you’ve been following up with my previous blogs, it is a continuity to my last blog on how to setup Zimbra mail server in CentOS. Till now, I’ve already covered the preparation and installation of ZCS package. From here, I’ll get into the post-installation part for our mail server setup. Changing SSH Port As we all already know, SSH daemon by default runs on port 22. So, it is a good practice to change it to some…

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Setup Zimbra Mail Server in CentOS

Setup Zimbra Mail Server in CentOS

Hello and welcome back to my next blog! In this post, I’m going to share how to setup Zimbra Mail Server in CentOS server. Since I’m going to cover this topic from start to end, it might be a long read and I hope you’ll manage to go through it. Just to give you a brief introduction of Zimbra, ZCS is one of the World’s largest open-source collaboration projects and it is an ideal solution for all sorts of mail related…

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Running vSRX Within GNS3 In Ubuntu

Running vSRX Within GNS3 In Ubuntu

Hello and welcome back! In this blog, I’m going to cover a little different topic than my previous ones. This time, it’s about setting up Juniper‘s vSRX within GNS3 in Ubuntu. To briefly introduce the involved subjects; vSRX is the virtual firewall appliance made by Juniper Networks, GNS3 is the best open-source network simulation software and Ubuntu is one of the most widely used Linux based operating systems. Installing GNS3 Installing GNS3 in Ubuntu is quite simple and easy. In…

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