blog
News & Updates
SELinux: Fix ‘Permission denied’ for swtpm (libvirt TPM Emulator) on Rocky Linux 10
KVM virtual machines won't start with "cannot execute binary /usr/bin/swtpm: Permission denied"? Learn how to fix SELinux blocking swtpm (TPM emulator) in 5 minutes. Complete guide with multiple solutions. You've just rebooted your KVM host after an upgrade, and your...
Postfix Postscreen Error: How to Fix ‘No such file or directory’ for LMDB Maps
Postfix postscreen failing with "error: open database …lmdb: No such file or directory"? Learn why this happens and how to fix it permanently in 2 minutes. Complete guide with scripts. You've just fixed the Postfix hash: to lmdb: conversion, but now you see this in...
Rocky Linux 10: Fix ‘unsupported dictionary type: hash’ Error in Postfix
Upgraded to Rocky Linux 10 and Postfix is failing with "unsupported dictionary type: hash"? Learn how to convert hash maps to LMDB in 5 minutes. Complete guide with scripts. You've just upgraded your mail server to Rocky Linux 10. Everything seemed fine until you...
Complete Guide: Securing a Rocky Linux KVM Host + Fixing Mail Server Dual-NIC Issues
Introduction Running a KVM host with multiple VMs requires careful security configuration. This guide documents real-world challenges including network instability, firewall issues, and a tricky dual-NIC routing problem on a mail server VM. Part 1: Initial Server...
iRedMail Backup & Disaster Recovery: Don’t Learn This the Hard Way
Here's a scenario no server administrator wants to face 🙂 You wake up to find your email server unresponsive. The disk has failed. Your hosting provider says the last backup is from 6 months ago. Your CEO is asking why no one can send or receive email. What do you...
Get Instant Server Alerts on Your Phone: Setting Up ntfy.sh with Fail2ban
Stop checking logs manually. Get instant push notifications when your server is attacked. Free, no registration, works with Fail2ban, Docker, cron jobs, and scripts. Complete setup guide for iOS and Android. You have fail2ban running. Your firewall is configured. Your...
iRedMail Security Hardening From Default to Production-Ready in 10 Minutes
Default iRedMail installations work but aren't secure. Follow this 10-point checklist to harden your mail server: SSL certificates, fail2ban, SASL authentication, firewall, PHP security, real-time alerts, and more. You've just installed iRedMail. Webmail works. Email...
The Complete iRedMail Upgrade Guide: From 1.7.4 to 1.8.2 on Red Hat, CentOS, Fedora, Rocky Linux 10.1
I recently upgraded two production iRedMail servers from version 1.7.4 to 1.8.2. The official documentation is excellent but assumes a perfect world. In reality, you'll encounter: PHP version mismatches (older OS versions) File permission issues after upgrade...
Step-by-Step Guide: Securing a Rocky Linux 10 KVM Host (SSH + Firewalld + Fail2Ban)
This guide explains how to securely configure a Rocky Linux 10 KVM virtualization host with proper network segmentation, SSH hardening, and intrusion protection using Fail2Ban and firewalld. Before You Start (IMPORTANT SAFETY RULE) Never apply firewall or SSH...
iRedMail Security Hardening: From Default to Production-Ready
Default iRedMail installation is not production-ready. Learn how to harden your mail server with SSL certificates, SASL authentication, firewall rules, fail2ban, root security, rate limiting, and monitoring. Congratulations! You've installed iRedMail. The web...
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...











