docs: update README to reflect internal mail server scope

Refactor the documentation to accurately describe the role as a complete internal mail server stack including Postfix and Dovecot.

Changes include:
- Expanded the description to explicitly list components and internal use cases.
- Added a section clarifying excluded features (antispam/antivirus).
- Reorganized role variables into General and Postfix configuration tables.
- Cleaned up Markdown formatting and removed excessive bold styling.
This commit is contained in:
2026-02-11 18:01:51 -03:00
parent b4930c3c7d
commit fc1900838b
4 changed files with 85 additions and 74 deletions

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README.md
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@@ -1,62 +1,76 @@
# **Ansible Role: Mail**
# Ansible Role: Mail
An Ansible role to install and configure Postfix on Debian-based systems.
An Ansible role to deploy and configure an internal mail server on Debian-based systems.
## **Description**
## Description
This role sets up Postfix to function as a local mail server designed for internal use. Its primary function is to accept mail from local services and relay all outbound messages through a configured **smarthost**.
This role sets up a complete internal mail server stack, currently including:
This is the perfect setup for environments where internal applications (like cron, monitoring systems, or web applications) need to send email notifications without the complexity of managing a full, internet-facing mail server.
- **Postfix** - Mail Transfer Agent (MTA) for sending and receiving mail
- **Dovecot** - IMAP/POP3 server for mail retrieval
This role performs the following actions:
The role is designed for **internal use cases** where applications, services, and users within your infrastructure need to send and receive email. Outbound mail is relayed through a configured smarthost (e.g., SendGrid, Mailgun, or your ISP's SMTP server).
* Installs the Postfix package and necessary SASL modules on Debian/Ubuntu.
* Manages the main Postfix configuration file (/etc/postfix/main.cf) via a template.
* Manages the /etc/mailname file for defining the mail domain.
* Configures Postfix to route all outgoing mail through a specified smarthost.
* Securely configures SASL authentication for the smarthost if credentials are provided.
### Use Cases
## **Requirements**
- Internal applications sending notifications (cron jobs, monitoring, CI/CD pipelines)
- Service accounts that need to receive and process email
- Development and testing environments
- Private mail infrastructure for small teams
* **Target OS**: This role is designed exclusively for **Debian-based** distributions (e.g., Debian, Ubuntu).
* **Ansible**: Version 2.10 or newer.
### What This Role Does NOT Include
## **Role Variables**
This role intentionally omits antispam and antivirus components. Since it's designed for internal mail that doesn't interact with external/untrusted sources, these features are unnecessary and would add complexity.
The role's behavior can be customized using the following variables. The default values are defined in defaults/main.yml.
## Requirements
| Variable | Default Value | Description |
| :---- | :---- | :---- |
| postfix_relayhost | "" (empty string) | **Required.** The smarthost for relaying all mail. Use square brackets [] to prevent MX lookups (e.g., \[smtp.sendgrid.net\]:587). |
| postfix_relayhost_user | (undefined) | The username for SASL authentication with the smarthost. If defined with a password, SASL auth will be enabled. |
| postfix_relayhost_password | (undefined) | The password or API key for the smarthost user. **It** is strongly recommended to store this in Ansible **Vault.** |
| postfix_mail_domain | `{{ ansible_domain \| default('internal.local') }}` | The primary mail domain for this server |
| postfix_myhostname | `mail.{{ postfix_mail_domain }}` | The fully qualified domain name (FQDN) of the mail server itself (e.g., mail.example.com). |
| postfix_mydestination | `$myhostname, localhost.{{ postfix_mail_domain }}, localhost, {{ postfix_mail_domain }}` | A comma-separated list of domains this server will accept mail for. The default is usually sufficient for an internal relay. |
| postfix_mynetworks | `"127.0.0.0/8 [::1]/128"` | The list of "trusted" remote SMTP clients that have more privileges than "strangers"|
| postfix_inet_interfaces | all | The network interfaces Postfix listens on. Set to loopback-only to only accept mail from the server itself. |
| postfix_inet_protocols | all | The IP protocols to use (ipv4, ipv6, or all). |
- **Target OS**: Debian-based distributions (Debian, Ubuntu)
- **Ansible**: Version 2.10 or newer
### **Dovecot Configuration**
## Role Variables
The role now supports installing and configuring Dovecot for IMAP/POP3 services.
Default values are defined in `defaults/main.yml`.
| Variable | Default Value | Description |
| :---- | :---- | :---- |
| dovecot_enabled | true | Whether to install and configure Dovecot. |
### General Settings
| Variable | Default | Description |
| :--- | :--- | :--- |
| mail_ssl_cert | snakeoil | Path to SSL certificate (shared by Postfix and Dovecot). |
| mail_ssl_key | snakeoil | Path to SSL private key (shared by Postfix and Dovecot). |
### Postfix Configuration
| Variable | Default | Description |
| :--- | :--- | :--- |
| postfix_relayhost | "" | **Required.** Smarthost for relaying outbound mail. Use brackets to skip MX lookups (e.g., `[smtp.sendgrid.net]:587`). |
| postfix_relayhost_user | (undefined) | Username for smarthost SASL authentication. |
| postfix_relayhost_password | (undefined) | Password/API key for smarthost. Store in Ansible Vault. |
| postfix_mail_domain | `{{ ansible_domain }}` | Primary mail domain for this server. |
| postfix_myhostname | `mail.{{ postfix_mail_domain }}` | FQDN of the mail server. |
| postfix_mydestination | `$myhostname, localhost...` | Domains accepted for local delivery. |
| postfix_mynetworks | `127.0.0.0/8 [::1]/128` | Trusted networks allowed to relay. |
| postfix_inet_interfaces | all | Network interfaces to listen on. Use `loopback-only` for local-only access. |
| postfix_inet_protocols | all | IP protocols to use (ipv4, ipv6, or all). |
SASL authentication for the smarthost is automatically enabled when both `postfix_relayhost_user` and `postfix_relayhost_password` are defined.
### Dovecot Configuration
| Variable | Default | Description |
| :--- | :--- | :--- |
| dovecot_enabled | true | Install and configure Dovecot. |
| dovecot_protocols | "imap pop3 lmtp" | Protocols to enable. |
| dovecot_mail_location | "maildir:~/Maildir" | Mail storage location. |
| dovecot_ssl | "yes" | SSL/TLS configuration (yes, no, required). |
| dovecot_ssl_cert | snakeoil | Path to SSL certificate. |
| dovecot_ssl_key | snakeoil | Path to SSL key. |
| dovecot_auth_mechanisms | "plain login" | Authentication mechanisms. |
| dovecot_postfix_sasl_enable | true | Enable Postfix SASL authentication via Dovecot. |
| dovecot_postfix_lmtp_enable | true | Enable Postfix delivery via Dovecot LMTP. |
| dovecot_users | [] | List of local users to create. See below. |
| dovecot_mail_location | "maildir:~/Maildir" | Mail storage format and location. |
| dovecot_ssl | "yes" | SSL/TLS mode: `yes`, `no`, or `required`. |
| dovecot_auth_mechanisms | "plain login" | Allowed authentication mechanisms. |
| dovecot_postfix_sasl_enable | true | Allow Postfix to authenticate users via Dovecot. |
| dovecot_postfix_lmtp_enable | true | Deliver mail to Dovecot via LMTP. |
| dovecot_imap_capability | "" | Adjust advertised IMAP capabilities (e.g., `+IMAP4rev1 -LITERAL+`). |
| dovecot_users | [] | List of virtual mailbox users. See below. |
### **Local Dovecot Users**
### Virtual Mailbox Users
You can define local users for Dovecot (e.g., for service accounts). These users are managed in a separate password file and use a generated token for security.
Define users for Dovecot virtual mailboxes:
```yaml
dovecot_users:
@@ -64,39 +78,37 @@ dovecot_users:
pass: "mysecretpassword"
```
The role will generate a random 16-character token on the server (stored in `/etc/dovecot/dovecot_token`). The actual password for the user will be `token + password`.
For example, if the token is `He5rN5SPH33AbFLn` and the password is `mysecretpassword`, the service must authenticate with `He5rN5SPH33AbFLnmysecretpassword`.
For security, the role generates a random 16-character token on the server (stored in `/etc/dovecot/dovecot_token`). The actual password is `token + password`. For example, if the token is `He5rN5SPH33AbFLn`, the user must authenticate with `He5rN5SPH33AbFLnmysecretpassword`.
### **SASL Authentication**
## Dependencies
SASL authentication for the smarthost is **automatically enabled** if both postfix_relayhost_user and postfix_relayhost_password are defined. If they are not defined, Postfix will attempt to send mail without authentication.
None.
## **Dependencies**
## Example Playbook
This role has no dependencies on other Ansible roles or collections beyond the standard ansible.builtin modules.
## **Example Playbook**
Here is a basic example of how to use this role in your playbook. You must define postfix_relayhost. It is also highly recommended to use Ansible Vault to encrypt the smarthost password.
```
---
- hosts: all
become: true
roles:
- role: your_username.postfix
vars:
postfix_relayhost: "[smtp.mailgun.org\]:587"
postfix_relayhost_user: "postmaster@mg.example.com"
postfix_relayhost_password: "{{ vaulted_mailgun_password }}" # Stored in Ansible Vault
postfix_inet_interfaces: "loopback-only"
```yaml
---
- hosts: mail_servers
become: true
roles:
- role: giacchetta.mail
vars:
postfix_mail_domain: "example.com"
postfix_relayhost: "[smtp.mailgun.org]:587"
postfix_relayhost_user: "postmaster@mg.example.com"
postfix_relayhost_password: "{{ vault_mailgun_password }}"
mail_ssl_cert: "/etc/letsencrypt/live/mail.example.com/fullchain.pem"
mail_ssl_key: "/etc/letsencrypt/live/mail.example.com/privkey.pem"
dovecot_ssl: "required"
dovecot_users:
- name: "alerts"
pass: "{{ vault_alerts_password }}"
```
## **License**
## License
GPL-3.0-only
## **Author Information**
## Author Information
This role was created by Giacchetta Networks.
This role was created by Giacchetta Networks.

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@@ -58,8 +58,8 @@ dovecot_mail_location: "maildir:~/Maildir"
# SSL/TLS configuration
# Use 'yes', 'no' or 'required'. 'required' is recommended for production.
dovecot_ssl: "yes"
dovecot_ssl_cert: "</etc/ssl/certs/ssl-cert-snakeoil.pem"
dovecot_ssl_key: "</etc/ssl/private/ssl-cert-snakeoil.key"
mail_ssl_cert: "/etc/ssl/certs/ssl-cert-snakeoil.pem"
mail_ssl_key: "/etc/ssl/private/ssl-cert-snakeoil.key"
# Authentication mechanisms
dovecot_auth_mechanisms: "plain login"

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@@ -2,5 +2,5 @@
# Ansible managed: {{ ansible_managed }}
ssl = {{ dovecot_ssl }}
ssl_cert = {{ dovecot_ssl_cert }}
ssl_key = {{ dovecot_ssl_key }}
ssl_cert = <{{ mail_ssl_cert }}
ssl_key = <{{ mail_ssl_key }}

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@@ -16,9 +16,8 @@ inet_interfaces = {{ postfix_inet_interfaces }}
recipient_delimiter = +
# TLS parameters for incoming connections
# For a production server, replace snakeoil with real certificates.
smtpd_tls_cert_file=/etc/ssl/certs/ssl-cert-snakeoil.pem
smtpd_tls_key_file=/etc/ssl/private/ssl-cert-snakeoil.key
smtpd_tls_cert_file={{ mail_ssl_cert }}
smtpd_tls_key_file={{ mail_ssl_key }}
smtpd_tls_security_level=may
smtpd_use_tls=yes