Lines of README.md from check-in aaa78fed23 that are changed by the sequence of edits moving toward check-in bdac638883:

                         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
                        24: api_key = "replace-with-your-telegram-bot-token"
                        25: api_gateway = "https://api.telegram.org"
                        26: listen_on = "127.0.0.1:1025"
                        27: fields = ["date", "from", "subject"]
                        28: domains = ["example.com", "localhost"]
                        29: 
                        30: default = 0
                        31: 
                        32: [recipients]
                        33: "admin@example.com" = 12345678
                        34: "alerts@example.com" = -10012345678
                        35: ```
                        36: 
                        37: All recipients are internally lowercased, so `UserName` equals `username`.
                        38: 
                        39: ---
                        40: 
                        41: ## Usage
                        42: 
                        43: ### Run
                        44: ```bash
                        45: ./smtp2tg -c /path/to/smtp2tg.toml
                        46: ```
                        47: 
                        48: ### CLI arguments
                        49: 
                        50: | Argument      | Description               | Example               |
                        51: |---------------|---------------------------|-----------------------|
                        52: | `-h`, `--help` | Show help                 | `smtp2tg --help`      |
                        53: | `-c`, `--config` | Path to config file     | `smtp2tg -c config.toml` |
                        54: 
                        55: ---
                        56: 
                        57: ## Security
                        58: 
                        59: ### Important
                        60: - **Recommended usage**: Run on `127.0.0.1` (localhost) only.
                        61: - If exposing to a network:
                        62:   - **Restrict port access** via firewall.
                        63:   - **Use TLS** (e.g., via `stunnel` or `nginx`).
                        64:   - **Implement authentication** (this software does not provide it).
                        65: 
                        66: ### Config file permissions
                        67: Set file permissions to `0600` (owner read/write only):
                        68: ```bash
                        69: chmod 600 smtp2tg.toml
                        70: ```
                        71: 
                        72: ---
                        73: ## How it works
                        74: 1. A client (e.g., Postfix) sends an email to `listen_on` (e.g., `127.0.0.1:1025`).
                        75: 2. smtp2tg parses the email and converts it to a Telegram message.
                        76: 3. The message is sent to the specified chat (or `default` if address is unknown).
                        77: 
                        78: ### Example: Email → Telegram
                        79: **Incoming email:**
                        80: ```text
                        81: From: user@example.com
                        82: To: admin@example.com
                        83: Subject: Test
                        84: 
                        85: Hello, world!
                        86: ```
                        87: 
                        88: **Telegram message:**
                        89: ```html
                        90: <blockquote expandable>
                        91: <u><i>Subject:</i></u> <code>Test</code>
                        92: <u><i>From:</i></u> <code>user@example.com</code>
aaa78fed23 2026-08-01   93: <u><i>Date:</i></u> <code>Mon, 01 Jan 2024 12:00:00 +0000</code>
                        94: </blockquote>
                        95: <pre>Hello, world!</pre>
                        96: ```
                        97: 
                        98: ---
                        99: ## Links
                       100: - **Original repository**: [http://fs.b1t.name/smtp2tg](http://fs.b1t.name/smtp2tg)
                       101: - **GitHub Mirror**: [https://github.com/kworr/smtp2tg](https://github.com/kworr/smtp2tg)