1. Create `smtp2tg.toml` (see `smtp2tg.toml.example` for reference).
2. Get a Telegram Bot Token from [@BotFather](https://t.me/BotFather).
3. Get your chat ID (use [@getidsbot](https://t.me/getidsbot) or debug mode in Telegram client).

### Example configuration
```toml
api_key = "123456789ABCdefGHIjklMNOpq"
api_key = "replace-with-your-telegram-bot-token"
api_gateway = "https://api.telegram.org"
listen_on = "127.0.0.1:1025"
unknown = "relay"
fields = ["date", "from", "subject"]
domains = ["example.com", "localhost"]

default = 0

### Run
```bash
./smtp2tg -c /path/to/smtp2tg.toml
```

### CLI arguments

| Argument      | Description               | Example               |
|---------------|---------------------------|-----------------------|
| `-h`, `--help` | Show help                 | `smtp2tg --help`      |
| `-c`, `--config` | Path to config file     | `smtp2tg -c config.toml` |

---

## How it works
1. A client (e.g., Postfix) sends an email to `listen_on` (e.g., `127.0.0.1:1025`).
2. smtp2tg parses the email and converts it to a Telegram message.
3. The message is sent to the specified chat (or `default` if address is unknown).

### Example: Email → Telegram
**Incoming email:**
```
```text
From: user@example.com
To: admin@example.com
Subject: Test

Hello, world!
```

**Telegram message:**
```
```html
<blockquote expandable>
<u><i>Subject:</i></u> <code>Test</code>
<u><i>From:</i></u> <code>user@example.com</code>
<u><i>Date:</i></u> <code>Mon, 01 Jan 2024 12:00:00 +0000</code>
</blockquote>
<pre>Hello, world!</pre>
```

---
## Links
- **Original repository**: [http://fs.b1t.name/smtp2tg](http://fs.b1t.name/smtp2tg)
- **GitHub Mirror**: [https://github.com/kworr/smtp2tg](https://github.com/kworr/smtp2tg)

	relay: bool,
	tg: Arc<TelegramTransport>,
	fields: HashSet<String>,
	address: Regex,
}

impl MailServer {
	/// Main asynchronous entry point for the application.
	/// Initializes the mail server: sets up the Telegram API client and
	/// validates all required configuration values.
	///
	/// Parses command-line arguments, loads configuration, and starts the SMTP
	/// server.
	/// # Arguments
	/// * `settings` - Parsed application configuration.
	///
	/// # Errors
	/// Returns an error if configuration is invalid, files are inaccessible, or
	/// Returns an error if required configuration values are missing or invalid.
	/// server fails to start.
	pub fn new(settings: config::Config) -> Result<MailServer> {
	pub fn new (settings: config::Config) -> Result<MailServer> {
		let api_key = settings.get_string("api_key")
			.context("[smtp2tg.toml] missing \"api_key\" parameter.\n")?;
		let mut recipients = HashMap::new();
		for (name, value) in settings.get_table("recipients")
			.expect("[smtp2tg.toml] missing table \"recipients\".\n")
		{
			let value = value.into_int()

		})
	}

	/// Retrieves the Telegram chat ID for a given email address, checks that
	/// used domain is allowed.
	///
	/// # Arguments
	/// * `name_str` - Email address or username to look up.
	/// * `name` - Email address or username to look up.
	///
	/// # Returns
	/// * `Result<ChatPeerId>` - Telegram chat ID for the address, or default if
	///   not found.
	pub fn get_id (&self, name: &str) -> Result<&ChatPeerId> {
		if self.address.is_match(name) {
			match self.tg.get(name) {
			Ok(self.tg.get(name).unwrap_or(&self.tg.default))
				Ok(addr) => Ok(addr),
				Err(_) => Ok(&self.tg.default),
			}
		} else {
			bail!("Doesn't look like address from one of our domains.");
		}
	}

	/// Attempt to deliver one message
	async fn relay_mail (&self) -> Result<()> {

	/// Just deny plain auth
	fn auth_plain (&mut self, _authorization_id: &str, _authentication_id: &str, _password: &str) -> Response {
		INVALID_CREDENTIALS
	}

	/// Verify whether address is deliverable
	fn rcpt (&mut self, to: &str) -> Response {
		if self.relay {
		if self.relay || self.get_id(to).is_ok() {
			OK
		} else {
			match self.get_id(to) {
				Ok(_) => OK,
				Err(_) => {
					if self.relay {
						OK
					} else {
						NO_MAILBOX
			NO_MAILBOX
					}
				}
			}
		}
	}

	/// Save headers we need
	fn data_start (&mut self, _domain: &str, from: &str, _is8bit: bool, to: &[String]) -> Response {
		self.headers = Some(SomeHeaders{
			from: from.to_string(),

//! Telegram API integration for sending messages and attachments.

use crate::utils::{
	Attachment,
	validate,
};

use std::{
	collections::HashMap,
	fmt::Debug,
};

use stacked_errors::{
	bail,
	Result,
	StackableErr,
};
use tgbot::{
	api::Client,
	types::{
		ChatPeerId,

	///
	/// # Arguments
	/// * `api_key` - Telegram Bot API token.
	/// * `recipients` - Mapping of email addresses to Telegram chat IDs.
	/// * `settings` - Additional configuration (API gateway, default chat).
	///
	/// # Errors
	/// Returns an error if configuration values cannot be read or if Telegram
	/// Returns an error if API client creation fails.
	/// API client creation fails.
	pub fn new (api_key: String, recipients: HashMap<String, i64>, settings: &config::Config) -> Result<TelegramTransport> {
		let default = settings.get_int("default")
			.context("[smtp2tg.toml] missing \"default\" recipient.\n")?;
		let api_gateway = settings.get_string("api_gateway")
			.context("[smtp2tg.toml] missing \"api_gateway\" destination.\n")?;

		let tg = Client::new(api_key)

	/// Sends a debug message to the default chat.
	///
	/// # Arguments
	/// * `msg` - Message text to send.
	///
	/// # Returns
	/// * `Result<Message>` - Telegram API response.
	///
	/// # Errors
	/// Returns an error if `msg` contains a closing Telegram tag or sending fails.
	pub async fn debug (&self, msg: &str) -> Result<Message> {
		self.send(&self.default, format!("<pre>{}</pre>", validate(msg).stack()?)).await
	}

	/// Retrieves a chat ID by name.
	///
	/// # Arguments
	/// * `name` - Name or email to look up.
	///
	/// # Returns
	/// * `Result<&ChatPeerId>` - Chat ID if found.
	///
	/// # Errors
	/// Returns an error if `name` is not configured.
	pub fn get (&self, name: &str) -> Result<&ChatPeerId> {
		self.recipients.get(name)
			.with_context(|| format!("Recipient \"{name}\" not found in configuration"))
	}

	/// Sends a text message to a specified chat.
	///

		).await.stack()
	}

	/// Sends a message with attachments to a specified chat.
	///
	/// # Arguments
	/// * `to` - Target chat ID.
	/// * `media` - List of attachments.
	/// * `media` - List of attachments, non-empty.
	/// * `msg` - Message text (supports HTML formatting).
	///
	/// # Returns
	/// * `Result<()>` - Success or error.
	pub async fn sendgroup (&self, to: &ChatPeerId, media: Vec<Attachment>, msg: &str) -> Result<()> {
		if media.len() > 1 {
			let mut attach = vec![];

						),
						caption
					)
				);
			}
			self.tg.execute(SendMediaGroup::new(*to, MediaGroup::new(attach).stack()?)).await.stack()?;
		} else {
			if media.is_empty() {
				bail!("At least one attachment is required.");
			}
			self.tg.execute(
				SendDocument::new(
					*to,
					InputFileReader::from(media[0].data.clone())
					.with_file_name(media[0].name.clone())
				).with_caption(msg)
				.with_caption_parse_mode(Html)
			).await.stack()?;
		}
		Ok(())
	}
}