1. Before you start

• Your domain A record points to the server IP

• Your website already opens on http://yourdomain.com

• Ports 80 and 443 are open in the firewall

• You have sudo/root access to the server

• Nginx or Apache is installed and serving your site

2. Option A — Easy way with aaPanel / hosting panel

• Open your website in the panel

• Go to SSL / Certificate

• Choose Let's Encrypt and issue the certificate

• Enable Force HTTPS

• Done — skip to the test section below

3. Option B — Install Certbot on Ubuntu

• Update packages: sudo apt update

• Recommended: sudo snap install --classic certbot

• Link command: sudo ln -s /snap/bin/certbot /usr/bin/certbot

• Or apt method: sudo apt install certbot python3-certbot-nginx (or python3-certbot-apache)

4. Issue SSL for Nginx

• Run: sudo certbot --nginx -d yourdomain.com -d www.yourdomain.com

• Enter email when asked

• Agree to terms

• Choose redirect HTTP → HTTPS when prompted

• Certbot edits Nginx and reloads it for you

5. Issue SSL for Apache

• Run: sudo certbot --apache -d yourdomain.com -d www.yourdomain.com

• Follow the same prompts as Nginx

• Confirm Apache reloads successfully

6. Test that SSL works

• Open https://yourdomain.com in a browser

• Check the lock icon / certificate details

• Confirm http:// redirects to https://

• Test auto-renewal: sudo certbot renew --dry-run

7. Common SSL errors

• DNS not pointing correctly — fix A record and wait for propagation

• Port 80 blocked — Let's Encrypt HTTP challenge needs port 80

• Wrong server block / vhost — ServerName must match the domain

• Too many failed attempts — wait and fix config before retrying

8. SSL vs email authentication

SSL protects your website connection. For email reputation you still need SPF, DKIM, and DMARC on sending domains. If you run outbound campaigns, use a mailer like Px Mailer for sending workflows, and keep SSL on your site/portals. Px Mailer: https://pxtoolx.com