Lines of README.md from check-in 880ce86a7f that are changed by the sequence of edits moving toward check-in 1723b63d69:

                         1: # smtp2tg
                         2: 
                         3: SMTP-to-Telegram gateway. Receives emails via SMTP and forwards them to Telegram chats.
                         4: 
                         5: ---
                         6: 
                         7: ## Installation
                         8: 
                         9: ### From source
                        10: ```bash
                        11: git clone https://github.com/kworr/smtp2tg
                        12: cd smtp2tg
                        13: cargo build --release
                        14: ```
                        15: 
                        16: ## Configuration
                        17: 
                        18: 1. Create `smtp2tg.toml` (see `smtp2tg.toml.example` for reference).
                        19: 2. Get a Telegram Bot Token from [@BotFather](https://t.me/BotFather).
                        20: 3. Get your chat ID (use [@getidsbot](https://t.me/getidsbot) or debug mode in Telegram client).
                        21: 
                        22: ### Example configuration
                        23: ```toml
880ce86a7f 2026-08-01   24: api_key = "123456789ABCdefGHIjklMNOpq"
                        25: api_gateway = "https://api.telegram.org"
                        26: listen_on = "127.0.0.1:1025"
                        27: unknown = "relay"
                        28: fields = ["date", "from", "subject"]
                        29: domains = ["example.com", "localhost"]
                        30: 
                        31: default = 0
                        32: 
                        33: [recipients]
                        34: "admin@example.com" = 12345678
                        35: "alerts@example.com" = -10012345678
                        36: ```
                        37: 
                        38: To catch bounces (so they wouldn't stuck in upper mail server) make sure sender
                        39: envelope address is real as required by mail library (actually not sure whether
                        40: this applies to mailin). For example Postfix has to be tweaked like this:
                        41: 
                        42: $config_directory/main.cf:
                        43: 	smtp_generic_maps = hash:$config_directory/generic
                        44: 
                        45: $config_directory/generic:
                        46: 	""	postmaster@example.com
                        47: 	<>	postmaster@example.com
                        48: 
                        49: Actually not sure which one works...
                        50: 
                        51: ---
                        52: 
                        53: ## Usage
                        54: 
                        55: ### Run
                        56: ```bash
                        57: ./smtp2tg -c /path/to/smtp2tg.toml
                        58: ```
                        59: 
                        60: ### CLI arguments
                        61: | Argument      | Description               | Example               |
                        62: |---------------|---------------------------|-----------------------|
                        63: | `-h`, `--help` | Show help                 | `smtp2tg --help`      |
                        64: | `-c`, `--config` | Path to config file     | `smtp2tg -c config.toml` |
                        65: 
                        66: ---
                        67: 
                        68: ## Security
                        69: 
                        70: ### Important
                        71: - **Recommended usage**: Run on `127.0.0.1` (localhost) only.
                        72: - If exposing to a network:
                        73:   - **Restrict port access** via firewall.
                        74:   - **Use TLS** (e.g., via `stunnel` or `nginx`).
                        75:   - **Implement authentication** (this software does not provide it).
                        76: 
                        77: ### Config file permissions
                        78: Set file permissions to `0600` (owner read/write only):
                        79: ```bash
                        80: chmod 600 smtp2tg.toml
                        81: ```
                        82: 
                        83: ---
                        84: ## How it works
                        85: 1. A client (e.g., Postfix) sends an email to `listen_on` (e.g., `127.0.0.1:1025`).
                        86: 2. smtp2tg parses the email and converts it to a Telegram message.
                        87: 3. The message is sent to the specified chat (or `default` if address is unknown).
                        88: 
                        89: ### Example: Email → Telegram
                        90: **Incoming email:**
880ce86a7f 2026-08-01   91: ```
                        92: From: user@example.com
                        93: To: admin@example.com
                        94: Subject: Test
                        95: 
                        96: Hello, world!
                        97: ```
                        98: 
                        99: **Telegram message:**
880ce86a7f 2026-08-01  100: ```
                       101: <blockquote expandable>
                       102: <u><i>Subject:</i></u> <code>Test</code>
                       103: <u><i>From:</i></u> <code>user@example.com</code>
                       104: <u><i>Date:</i></u> <code>Mon, 01 Jan 2024 12:00:00 +0000</code>
                       105: </blockquote>
                       106: <pre>Hello, world!</pre>
                       107: ```
                       108: 
                       109: ---
                       110: ## Links
                       111: - **Original repository**: [http://fs.b1t.name/smtp2tg](http://fs.b1t.name/smtp2tg)
                       112: - **GitHub Mirror**: [https://github.com/kworr/smtp2tg](https://github.com/kworr/smtp2tg)