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Showing posts from 2021

How to change default system email for root@hostname for Postfix in CentOS 7?

By default, any system email is generated by system is sent to root@hostname or system-user@hostname . So critical server errors, log errors, corn jobs alerts etc. all are sent to this default email address. Most likely you want to receive all the emails from different daemons and system components not to the user ‘root ’ but in another user that has access to emails.  To change it to different appropriate email id, we can do this by two ways.  Step 1: To do this, open /etc/aliases with your favourite editor and navigate to the end of the file. You will find something like this: # vi /etc/aliases root: To add multiple email ids, we can simply separate them by comma. root:, Run the aliases command, to compile aliases file. # newaliases # service postfix restart Step 2: We can simply create .forward file to the folder root and add email address there. # vi /root/.forward serveradmin@awsmo

How to install unrar with Clamav for MailScanner?

The unrar command is used to extract, list or test archive files only .ClamAV will need unrar, it can be installed from rpmforge repository , so: # cd /usr/local/src/ # wget # rpm -ivh rpmforge-release-0.5.3-1.el7.rf.x86_64.rpm # yum update -y # yum install unrar # rpm --import /etc/pki/rpm-gpg/RPM-GPG-KEY-rpmforge-dag Note: RPMForge is now RepoForge & might be outdated. There is no updates since very long time. After installing unrar, Disabled rpmforge repo:  # sed -i 's/enabled = 1/enabled = 0/g' /etc/yum.repos.d/rpmforge.repo # yum update -y Viruses are commonly spread as attachments to email messages. Install the following packages for Amavis to extract and scan archive files in email messages such as .7z, .cab, .doc, .exe, .iso, .jar, and .rar files. # yum install arj bzip2 cpio file gzip nomarch spax unrar p7zip unzip zip lrzsz lzip lz4 lzop FreshClam Setup:  freshclam will update the virus signatur

How to Secure Postfix/Dovecot on CWP Email Server on CentOS 7?

At first I would like thank to CWP team for their great effort at $11.99. It has corporate mail features better than Cpanel and others. BTW It's my personal opinion. CWP team has changes many options on Postfix and Dovecot Configuration. It is very important to secure Postfix & Dovecot for Production server that will never expose your internal office or user home network. I did some little research and studies a lot to learn Postfix & Dovecot configuration. Lets Explain my scenario:  I have a VPS and it has two IPs. Both IP has valid PTR records . You must configure a valid FQDN for your IPs. My Details are below:  My Primary Domain:  Server FQDN :  ---  (IP for Shared Hosting) Sub-Domain   :  ---  (IP for sending Outgoing Email) Now build your Mail Server with the following options that mentioned in below snapshot You can follow the link to Build your own CWP Mail Server How to Bu

Part 2: How to install Wildcard SSL to Nginx Load Balancer on Ubuntu 18.04 LTS ?

In previous tutorial We already installed and secured our Nginx Load Balancer. In this part, We are going to use Let's Encrypt Wildcard SSL for our domain. It is a free, automated, and open Certificate Authority. That means you do not need to pay charges for SSL Certificate.  Part 1: How to Configure Nginx as a Web/HTTP/HTTPS Load Balancer on Ubuntu 18.04 LTS ? Once you are logged in to your server, you need to install certbot to process further. (Certbot is not available in the default ubuntu repository.) Run the below command to add ppa repository. # sudo add-apt-repository ppa:certbot/certbot # apt update -y # apt list --upgradable # apt upgrade -y # sudo apt install certbot # apt-cache policy certbot | grep -i Installed Generate 2048 bits Wildcard SSL for # certbot certonly --manual --preferred-challenges=dns --email --server --agree-tos -d * -d Now you nee

Part 1: How to Configure Nginx as a Web/HTTP/HTTPS Load Balancer on Ubuntu 18.04 LTS ?

Load balancing across multiple application instances is a commonly used technique for optimizing resource utilization, maximizing throughput, reducing latency, and ensuring fault-tolerant configurations.  It is possible to use nginx as a very efficient HTTP load balancer to distribute traffic to several application servers and to improve performance, scalability and reliability of web applications with nginx. The following load balancing mechanisms (or methods) are supported in nginx:   round-robin: requests to the application servers are distributed in a round-robin fashion,  least-connected: next request is assigned to the server with the least number of active connections,  ip-hash: a hash-function is used to determine what server should be selected for the next request (based on the client’s IP address).   Note: Please note that with round-robin or least-connected load balancing, each subsequent client’s request can be potentially distributed to a different server. There is no

How to install development tools on Debian or Ubuntu 16.04 LTS ?

Development tools are required to install on your system if you have planned to build software. It’s also useful for building packages on your system. To install development tools on a server running Debian or Ubuntu, follow these steps: # apt-get update -y # apt-get install build-essential # apt-get install autoconf automake gdb git libffi-dev zlib1g-dev libssl-dev # sudo apt install libcurl4-gnutls-dev libxml2-dev # reboot If you want to install R Packages using DevTools, Follow the below Link:

VestaCP Tweaks : Vesta Dashboard Customization

VestaCP is a free and Best hosting control panel ever i used. Very fast and light weight control than others Control Panel. I am using Ubuntu 16.04 LTS. In today’s guide, I’m going to show you some customization for your Branding purposes But this is not recommended by VestaCP.   1. How to Change Default Index Page ? Default Index page Location: # vi /usr/local/vesta/data/templates/web/skel/public_html/index.html 2. Change Default Page using Gist :  3. Create php info page to collect PHP information <?php // Show all information, defaults to INFO_ALL phpinfo(); ?> 4. Rename apache2 default index page [  Don't restart apache2, because we are using nginx  # service apache2 restar t [Don't restart apache2] # mv /var/www/html/index.html /var/www/html/index.html.old # cp -a /usr/local/vesta/data/templates/web/skel/public_html/index.html /var/www/html/ 5. Change Vesta Admin Port # vi /usr/local/vesta/nginx/conf/nginx.conf 6. Set Host