📨 ansible-smtp

Ansible playbook to set up an SMTP mail server with the following components:

• Postfix: A free and open-source Mail Transfer Agent (MTA) that routes and delivers email.
• Dovecot: An open-source IMAP and POP3 server for email retrieval and storage.

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🚀 Run the Playbook

Use the following command to set up your mail server:

ansible-playbook -i inventory --user=root --become setup-mailserver.yml --tag setup

🧩 Service Status

Check whether the mail services are running:

systemctl status dovecot
systemctl status postfix

🧪 Testing (Development Mode)

When developing or testing, you can easily destroy the host environment:

ansible-playbook -i inventory --user=root --become setup-mailserver.yml --tag destroy

⚠️ Note:
Running the playbook without specifying a tag will execute both setup and destroy tasks, effectively canceling each other out.

📧 Test Sending Email (Local)

Install mail utilities and send a test email:

sudo apt-get install mailutils -y   # For Debian/Ubuntu
echo "This is a test email" | mail -s "Test Email" -r test@smtp.domain.at me@example.com

🌐 Test Sending Email from External Services

1. Set your desired test user in defaults/main.yml.
2. On your local client machine, run:

sudo apt-get install swaks -y  # For Debian/Ubuntu
swaks -t me@example.com -s mail.example.com:587 -tls -a LOGIN

You’ll be prompted for a username and password — enter the credentials of your test user. If successful, an email should arrive at the specified destination address.

🧰 Debugging and Logs

Check recent logs for Dovecot or Postfix:

journalctl -u dovecot --since "10 minutes ago"
journalctl -u postfix --since "10 minutes ago"

If you’re using Let’s Encrypt for certificates, view the Certbot logs here:

cat /var/log/letsencrypt/letsencrypt.log

🔐 Allowed IPs

You can configure which IPs are allowed to relay mail through the server by editing:

roles/mailserver/defaults/main.yml

The variable that controls this is mynetworks.

This is used both directly for the permit_mynetworks restriction and to generate the Postfix access table.

💡 Examples:

# Localhost + Private subnets
mynetworks: 127.0.0.0/8 163.221.23.0/20 11.12.0.0/16 13.109.0.0/20

# IPv4 + IPv6 localhost
mynetworks: 127.0.0.0/8 [::1]/128

# Public single IPs
mynetworks: 122.21.216.176/32 163.221.23.0/32