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Securing iRedMail with Fail2ban: Beyond the Default Configuration.
Fail2ban is installed but are you getting alerts? Learn how to configure fail2ban for iRedMail, fix broken jails, and set up real-time notifications via email and Telegram. Your iRedMail server is being attacked. Right now. Open your mail logs and you'll see a...
Why Your iRedMail Emails Go to Spam (or Never Arrive) and How to Fix It!
Emails from your iRedMail server going to Gmail spam folder? Learn how to set up SPF, DKIM, DMARC, PTR records, and warm up your IP address for perfect deliverability. You've set up iRedMail. SSL certificates are working. Authentication is perfect. But there's one...
Apple Mail Cannot Connect to iRedMail? Here’s the Fix
Apple Mail throwing "Unable to verify account name or password" errors with your iRedMail server? Learn the correct settings for IMAP, SMTP, SSL, and authentication that actually work. Suggested Featured Image Prompt: You've followed every tutorial. You've...
Firewalld Says Ports Are Open But Connections Fail: The SMTP Port Mystery
You've opened ports 465 and 587 in firewalld, but connections still fail. Learn why rich rules, zones, and service definitions matter. Fix your email server firewall once and for all. You've run the command. You've double-checked it twice: sudo firewall-cmd...
Remove ‘Untrusted Certificate’ Errors in Apple Mail, Outlook, and Thunderbird for iRedMail
Tired of "untrusted certificate" warnings in your email client? Replace iRedMail's self-signed SSL certificates with free Let's Encrypt certificates. Step-by-step guide for Rocky Linux, Ubuntu, and more. You've just set up iRedMail and created your first email...
Postfix SASL Authentication Failed: Fixing ‘No SASL authentication mechanisms’ in iRedMail
You've just set up iRedMail, configured your domains, and created email accounts. Everything seems perfect until you try to send an email from your desktop client. Instead of a sent confirmation, you're staring at an error message in your mail logs: warning: SASL:...
How to Set Up Let’s Encrypt SSL for iRedMail on Rocky Linux 10.1, RHEL, CentOS, Fedora, and Ubuntu
Introduction iRedMail is a powerful open-source mail server solution that comes with self-signed SSL certificates by default. While self-signed certificates work, they trigger security warnings in email clients like Apple Mail, Outlook, and Thunderbird. This tutorial...
nmcli Complete Command Guide
Essential Examples for System Administrators (Bridge, VLAN, and SSH Safety) NetworkManager's command-line tool nmcli is a powerful utility for managing network connections on Linux servers. For system administrators, mastering nmcli is essential—it allows you to...
How to Manage Plesk Firewall from the Command Line: A Complete Guide
Introduction Managing firewall rules through Plesk's web interface is straightforward, but there are times when you only have SSH access to your server. Whether you're troubleshooting a lockdown situation, automating server configuration, or simply prefer the command...
How to Install Kali Linux Natively on a Mac: Complete Step-by-Step Guide
Are you a cybersecurity enthusiast or penetration tester looking to run Kali Linux directly on your Mac hardware? While virtual machines are convenient, nothing beats the performance of a bare-metal installation. This comprehensive guide will walk you through...
Monitor your KVM host, RAID arrays, and security status with beautiful automated HTML daily report.
How to Set Up a Professional Daily Server Report with HTML Email on Rocky Linux 8/9/10 As a system administrator, staying on top of your server's health is crucial. In this comprehensive guide, I'll show you how to create a fully automated daily server report system...
Hardening Ubuntu Servers: A Comprehensive Guide to OpenSCAP and Ubuntu Security Guide (USG)
In today's threat landscape, security compliance isn't optional—it's essential. Whether you're running a single server or managing an enterprise infrastructure, knowing your security posture is the first step toward protecting your systems. Two powerful tools stand...