Skip to main content

✉️ Deploying the Poste.io Mail Server

Poste.io is a complete solution for managing email servers with a web panel, support for TLS/SSL, SPF, DKIM, integrated antivirus, and antispam. This documentation guides you through deploying the application via the SaveinCloud Marketplace.

🚀 How to Install​

  1. Access the SaveinCloud Panel.
  2. Search for Poste.io in the Marketplace.
  3. Click Install.
  4. Fill in the fields:
    • Platform Hostname
    • Display Name
    • Datacenter Region

❗ Important: To use Poste.io correctly, you need an external domain (do not use only the platform hostname).

📦 Provisioned Environment​

A Docker environment will be created with the following docker-compose.yaml:

version: '3'

services:
  mailserver:
    image: analogic/poste.io
    container_name: poste
    restart: always

    ports:
      - "80:80"
      - "443:443"
      - "25:25"
      - "110:110"
      - "143:143"
      - "587:587"
      - "993:993"
      - "995:995"
      - "4190:4190"

    environment:
      - TZ=America/Sao_Paulo
      - h=change-me.here
      - HTTP_PORT=80
      - HTTPS_PORT=443

    volumes:
      - /etc/localtime:/etc/localtime:ro
      - /data/mailserver:/data

🧠 The value h=change-me.here must be edited manually after provisioning.

🛠️ Adjusting the Hostname in YAML​

After the environment is running:

  1. Access the instance terminal.
  2. Run: 
    nano /home/poste/docker-compose.yaml
  3. Locate the line: 
    - h=change-me.here
  4. Replace it with your domain (example): 
    - h=mail.seudominio.com.br
  5. Save and restart the environment: 
    docker-compose down && docker-compose up -d

🌐 DNS Configuration​

For proper operation, configure the following DNS records at your provider (e.g., Registro.br, Cloudflare):

TypeNameValue
Amail.yourdomain.com[Public IP of the instance]
MX@mail.yourdomain.com
TXT@v=spf1 mx ~all
TXT_dmarcv=DMARC1; p=none;
TXTdefault._domainkey(provided after DKIM is active)

🔐 SaveinCloud does not provide DNS/Nameserver — use your domain's control panel.

🧪 Initial Setup​

Access the URL:

http://mail.seudominio.com.br/admin/install/server

You will see the following screen:

📌 First poste.io configuration

  • Mailserver hostname: Fill in with mail.seudominio.com.br
  • Administrator email: Will be filled automatically.
  • Password: Create the administrator password. Primeiro acesso ao ambiente do posteio Click Submit to complete the initial setup.

👤 Creating Email Accounts​

  1. Access the panel: http://mail.seudominio.com.br/admin/box/ Dashboard inicial do posteio
  2. Go to Email accounts
  3. Click Create a new email
  4. Fill in the account details (name, password)

You can also create:

  • Redirect (alias) for forwarding
  • Alias for alternative addresses

🔒 Enabling HTTPS with Let's Encrypt​

To issue a free TLS certificate:

  1. Access: System settings > TLS Certificate

  2. Click Issue free letsencrypt.org certificate Caminho para chegar no TLS Certificate e Lets encrypt

  3. Check the Enabled option

  4. Click Save changes Habilitar o certificado letsencrypt

Within seconds, your domain will have HTTPS enabled and be Ready to Use.

📬 Accessing Webmail (Roundcube)​

Poste.io comes with Roundcube Webmail integrated, allowing users of created email accounts to access, send, and receive messages directly through the browser.

🔑 Access URLs​

  • Admin Panel:
    Accessible via: mail.yourdomain.com/admin/

    Use the administrator account created during the initial setup to access the Poste.io admin panel.

  • Webmail (Roundcube):
    Accessible via: mail.yourdomain.com/webmail
    Acesso da Caixa de entrada das contas via roundcube
    Users can log in with the email and password created in the Poste.io panel.
    Caixa de entrada da conta admin

    💡 Example login:
    [email protected] + defined password

🧪 Interface​

The Roundcube interface is modern, responsive, and supports:

  • Sending and receiving emails
  • Folder creation
  • Filters, auto-replies, and signatures
  • Multi-language support
  • Attachments and HTML

🛡️ Note: To ensure a secure connection, make sure the TLS certificate was successfully issued for the domain. Otherwise, the browser may show "not secure site" warnings.

⚙️ Environment Specifications​

  • Environment Type: Dockerized via Compose
  • Persistence: Volume at /data/mailserver
  • Resources: 28 Cloudlets
    (Each cloudlet = 400MHz CPU + 128MiB RAM ≈ 11.2GHz + 3.5GB RAM)
  • Exposed Ports:
    • 80 (HTTP)
    • 443 (HTTPS)
    • 25, 587 (SMTP)
    • 110, 995 (POP3)
    • 143, 993 (IMAP)
    • 4190 (Sieve)

📝 Final Notes​

  • The TLS certificate will only be issued if the domain is correctly pointed with an A record to the environment's IP.
  • On first access, the browser may show a "not secure site" warning. This is normal until HTTPS is active.