fossbilling-mailgateway/README.md

# Mail Gateway for FOSSBilling

Mail Gateway imports email into FOSSBilling support tickets using the existing
FOSSBilling cron. Configure multiple IMAP mailboxes and route each one to a
separate helpdesk.

## Features

- Create customer tickets from recognised email addresses and guest tickets from unknown senders.
- Add replies to existing tickets using the ticket number in the subject.
- Check that the sender owns the ticket before accepting a reply.
- Filter recognised automatic messages and prevent duplicate imports.
- Move handled emails into Processed, Ignored or Failed folders.
- Manage mailbox connections and test them from the admin settings page.

## Requirements

- FOSSBilling with the Support module enabled and its cron running regularly.
- An IMAP server supporting native `MOVE` and a valid TLS certificate when using TLS.
- A receiving mail server with appropriate email authentication and anti-spoofing policies.
- The `webklex/php-imap` Composer package and its required PHP extensions.

The native PHP IMAP extension is not required. Composer checks dependency
requirements when installing. For installation through the settings page, the
web server also needs access to PHP CLI, Composer, `proc_open`, a writable module
directory and package downloads. If web installation is unavailable or the module
directory is deliberately not writable by the web server, installation over SSH
is the preferred fallback. Run this from the module directory as its owning user:

```bash
composer install --no-dev --prefer-dist --no-interaction --no-scripts --no-plugins --optimize-autoloader
```

This uses the supplied lock file. The web server still needs read access to the
installed dependencies; it does not need write access to them for importing.

## Installation

1. Place the module in `modules/Mailgateway`.
2. Activate Mail Gateway in FOSSBilling. Activation creates the module tables,
   registers its sender-mismatch email template and attempts to install dependencies.
3. Open Mail Gateway's settings from the Extensions page. If dependencies were
   not installed automatically, use **Install dependencies** or run
   `composer install` in the module directory.
4. Configure the receiving email address, helpdesk, IMAP connection details and
   inbox and destination folders, then save.
5. Select **Test Connection and Create Folders**. This verifies the connection
   and creates missing destination folders without processing emails.
6. After a successful test, enable mailbox importing and save again. This also
   configures ticket acknowledgement and notification subjects automatically.

**Notification template changes persist:** enabling importing or running
**Configure ticket notifications** enables the ticket acknowledgement and adds
missing ticket references to existing FOSSBilling notification subjects. These
changes apply to those templates throughout FOSSBilling. Disabling or uninstalling
Mail Gateway does not restore their original subjects or enabled state. If you
want to restore them later, keep a copy of the original settings and edit the
templates manually in FOSSBilling's Email settings.

Use **Add mailbox** to configure additional addresses. Each mailbox has its own
connection details, folders and helpdesk. All four folder paths must be distinct;
the inbox must already exist.

Importing remains disabled until dependencies are installed and the mailbox has
passed its connection and folder test. Changing connection details or folder
paths requires another successful test. The settings page shows the results and
explains any failures.

No additional cron entry is needed. The module polls every five minutes by
default, provided the FOSSBilling cron runs that often.

## Tickets and replies

Email from a customer's primary email address creates a customer ticket.
Unknown senders create guest tickets when guest tickets are enabled in Support.
New tickets go to the mailbox's selected helpdesk.

Replies are matched by a subject marker such as `[Ticket #123]`. The sender must
own the referenced ticket. Emails without a ticket marker create a new ticket;
reply headers are not used for matching.

Sender matching uses the email's From address; it does not prove that the sender
controls that address. Mail Gateway does not independently verify SPF, DKIM or
DMARC, and relies on the receiving mail server to apply authentication and
anti-spoofing policies before mail reaches the imported inbox. Configure those
policies to reject or quarantine suspicious messages outside that inbox.
A forged message accepted into the inbox could impersonate a customer or the
owner of a guest ticket. Guest reply ownership is based on the original sender's
email address, without an authenticated customer account.

Enabling mailbox importing automatically enables the `mod_support_ticket_open`
acknowledgement and adds `[Ticket #{{ ticket.id }}]` to its subject and enabled
staff notification subjects where missing. Existing wording is preserved and
disabled optional staff notifications stay disabled. Notifications are delivered
through FOSSBilling's email queue.

For an existing mailbox, use **Advanced → Configure ticket notifications** to run
the same setup. Notification status is shown in Advanced, with any problems also
displayed at the top of the page. Setup does not send test emails. You can edit
notification wording in FOSSBilling's Email settings; keep the ticket marker in
subjects so replies can be matched.

The included `mailgateway_sender_mismatch` template uses your company name and
email signature to tell senders when their address does not match the referenced
ticket. It is installed only if missing. Its wording can be edited or the
notification disabled in Email settings. Existing custom templates are preserved.

Messages use plain text when available, with HTML converted to text otherwise.
Quoted reply history is retained. Attachments stay in the archived email and are
not attached to tickets.

## Email handling

| Result | Destination |
| --- | --- |
| Imported ticket, reply or duplicate | Processed |
| Recognised automatic message | Ignored |
| Invalid message or rejected reply | Failed |
| Temporary connection or database failure | Inbox, for retry |

Only the configured inbox is imported, including already-read messages.
Duplicate tracking prevents repeated imports, including when a folder move needs
to be retried. To retry a rejected email after resolving its cause, move it from
Failed back to the inbox.

Recognised automatic messages receive no response. Unmarked automatic messages
cannot always be identified; a notification cooldown limits automated
acknowledgements and sender-mismatch notices to one per sender per hour by default.

## Configuration and maintenance

Mailbox settings are stored in the database, with passwords encrypted using
FOSSBilling's encryption helper. Leaving a password blank keeps the saved value;
use the password-clearing option to remove it.

Operational settings are in `config.php`, including polling limits, timeouts,
message size limits, notification cooldown and executable paths. Edit this file
over SSH; changes take effect on the next cron run or web request. By default,
each run handles up to 50 messages per mailbox, with a shared 90-second time
budget. Complete emails are limited to 5 MiB and ticket bodies to 65,535 bytes.

The settings page's **Advanced** section provides notification setup, Composer
installation and table setup. Table setup creates missing tables and the default
mismatch template without deleting existing data or replacing customised templates.

Deleting a mailbox removes its configuration while keeping emails, folders,
tickets and message tracking.

The following commands are available from the module directory:

```bash
# Test a saved mailbox without processing emails.
php tools/test-imap.php

# Test another mailbox and create missing destination folders.
php tools/test-imap.php --mailbox=billing@example.com --create-folders

# Import mail immediately.
php tools/poll.php --force

# Create missing tables and register the default email template.
php tools/setup.php
```

A connection test with `--create-folders` records the mailbox's readiness, just as
the settings-page test does. A read-only test does not change readiness.

## Compatibility note

The module loads its own Composer dependencies into the same PHP process as
FOSSBilling. Shared Symfony or Illuminate packages are not isolated by the module's
separate `vendor` directory. Check installation, connection testing and importing
on your FOSSBilling version before deploying; compatibility across clean
FOSSBilling installations and versions has not yet been established.

During imported ticket creation, the module temporarily wraps FOSSBilling's
`mod_service` factory to intercept email calls. This applies the acknowledgement
cooldown and suppresses the separate canned-response email while retaining its
ticket history. Other module lookups are delegated to the original factory,
which is restored in a `finally` block, including when creation fails.

Ticket-creation hooks also see this wrapped factory: email services obtained
during that scope are proxies, and matching notification codes are intercepted.
The installed FOSSBilling notification interfaces provide no per-ticket
suppression option. This integration should be reviewed when upgrading
FOSSBilling or adding hooks that send emails during ticket creation.

## License

MIT. See [LICENSE](LICENSE).