diff --git a/Cargo.toml b/Cargo.toml
index ce75883..45e6340 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -8,6 +8,7 @@ license = "MIT OR Apache-2.0"
 publish = false
 
 [dependencies]
+clap = { version = "4.1.13", default-features = false, features = ["std", "derive", "help", "usage"] }
 env_logger = "^0.10"
 log = "^0.4"
 mailparse = "^0.14"
diff --git a/src/config.rs b/src/config.rs
new file mode 100644
index 0000000..76beea1
--- /dev/null
+++ b/src/config.rs
@@ -0,0 +1,40 @@
+use clap::Parser;
+use std::collections::HashSet;
+use std::fs::File;
+//use std::io::BufReader;
+use std::io::{BufRead, BufReader};
+use std::path::PathBuf;
+
+#[derive(Parser, Debug)]
+#[command(author, version, about, long_about = None)]
+pub struct Config {
+	#[arg(short, long)]
+	domain: Vec<String>,
+	#[arg(short = 'D', long, value_name = "FILE")]
+	domain_file: Option<PathBuf>,
+	#[arg(short, long, value_name = "FILE")]
+	revocation_list: Option<PathBuf>,
+}
+
+impl Config {
+	pub fn init() -> Result<Self, String> {
+		let mut cnf = Self::parse();
+		let mut domain_set: HashSet<String> = cnf.domain.into_iter().collect();
+		if let Some(path) = &cnf.domain_file {
+			let f = File::open(path).map_err(|e| format!("{}: {e}", path.display()))?;
+			for line in BufReader::new(f).lines() {
+				let line = line.map_err(|e| format!("{}: {e}", path.display()))?;
+				let domain = line.trim();
+				if !domain.is_empty() && !domain.starts_with('#') {
+					domain_set.insert(domain.to_string());
+				}
+			}
+		}
+		cnf.domain = domain_set.into_iter().collect::<Vec<_>>();
+		Ok(cnf)
+	}
+
+	pub fn domains(&self) -> &[String] {
+		&self.domain
+	}
+}
diff --git a/src/main.rs b/src/main.rs
index fe5c3f4..cdb75a3 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -1,4 +1,5 @@
 mod canonicalization;
+mod config;
 mod entry;
 mod handshake;
 mod logs;
@@ -43,6 +44,16 @@ macro_rules! log_messages {
 
 fn main() {
 	logs::init_log_system();
+	match config::Config::init() {
+		Ok(cnf) => {
+			log::debug!("{cnf:?}");
+			main_loop(&cnf)
+		}
+		Err(e) => log::error!("{e}"),
+	}
+}
+
+fn main_loop(cnf: &config::Config) {
 	let mut reader = StdinReader::new();
 	let mut messages: HashMap<String, Message> = HashMap::new();
 	handshake::read_config(&mut reader);
@@ -59,7 +70,7 @@ fn main() {
 							msg.append_line(entry.get_data());
 						} else {
 							log::debug!("message ready: {msg_id}");
-							msg.sign_and_return();
+							msg.sign_and_return(&cnf);
 							messages.remove(&msg_id);
 							log::debug!("message removed: {msg_id}");
 						}
@@ -71,7 +82,7 @@ fn main() {
 							messages.insert(msg_id, msg);
 						} else {
 							log::debug!("empty new message: {msg_id}");
-							msg.sign_and_return();
+							msg.sign_and_return(&cnf);
 						}
 					}
 				}
diff --git a/src/message.rs b/src/message.rs
index 4cb78e1..2276f94 100644
--- a/src/message.rs
+++ b/src/message.rs
@@ -1,3 +1,4 @@
+use crate::config::Config;
 use crate::entry::Entry;
 use mailparse::parse_mail;
 use std::io::{BufWriter, Write};
@@ -50,7 +51,7 @@ impl Message {
 		self.nb_lines
 	}
 
-	pub fn sign_and_return(&self) {
+	pub fn sign_and_return(&self, cnf: &Config) {
 		log::trace!("content:\n{}", crate::display_bytes!(&self.content));
 		match parse_mail(&self.content) {
 			Ok(parsed_msg) => {