Hello everyone, Technical Sahil here. In this video I show you my complete step-by-step process to install and configure Mailu mail server on Ubuntu 22.04. I start with the real requirements that actually matter in production: you need a domain, a server with at least 4GB RAM, and most importantly port 25 must be open. I also explain why I prefer using providers that give clean IPs, because if your IP is blacklisted (Spamhaus, UCEPROTECT, etc.), Gmail/Outlook inboxing becomes a headache from day one. I even check IP reputation first so we don’t waste time later. After that, I configure the basic DNS (A record for mail, custom MX pointing to mail.yourdomain, and the hostname/PTR part where applicable), then update packages, enable UFW, and allow the required TCP ports. Next I install Docker + Docker Compose, verify Docker is working, and generate the Mailu config from setup.mailu.io (don’t copy someone else’s env keys—these are unique). Finally, I create the admin user, log into the /admin panel, create mail users, and set up SPF, DKIM, and DMARC properly (without the double quotes mistake) to improve deliverability. At the end I also share a real-world issue I faced: Roundcube/webmail and some SMTP testing tools didn’t behave as expected (likely STARTTLS/tool-side limitations). The core setup is correct, so if you hit the same testing problem, follow the same checklist and I’ll cover fixes separately.