diff --git a/src/entry.rs b/src/entry.rs
index 81ca0fc..72dee66 100644
--- a/src/entry.rs
+++ b/src/entry.rs
@@ -9,6 +9,10 @@ pub struct Entry {
 }
 
 impl Entry {
+	pub fn get_msg_id(&self) -> String {
+		format!("{}.{}", self.session_id, self.token)
+	}
+
 	pub fn get_session_id(&self) -> &str {
 		&self.session_id
 	}
diff --git a/src/main.rs b/src/main.rs
index 90be7d6..7cf1d02 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -1,23 +1,42 @@
 mod entry;
 mod handshake;
+mod message;
 mod stdin_reader;
 
 use entry::Entry;
+use message::Message;
+use std::collections::HashMap;
 use stdin_reader::StdinReader;
 
 const DEFAULT_BUFF_SIZE: usize = 1024;
 
 fn main() {
 	let mut reader = StdinReader::new();
+	let mut messages: HashMap<String, Message> = HashMap::new();
 	handshake::read_config(&mut reader);
 	handshake::register_filter();
 	loop {
 		match Entry::from_bytes(&reader.read_line()) {
 			Ok(entry) => {
-				if !entry.is_end_of_message() {
-					println!("Debug: {entry:?}");
-				} else {
-					println!("Debug: end of message: {entry:?}");
+				let msg_id = entry.get_msg_id();
+				match messages.get_mut(&msg_id) {
+					Some(msg) => {
+						if !entry.is_end_of_message() {
+							msg.append_line(entry.get_data());
+						} else {
+							msg.sign_and_return();
+							messages.remove(&msg_id);
+						}
+					}
+					None => {
+						if !entry.is_end_of_message() {
+							let msg = Message::from_line(entry.get_data());
+							messages.insert(msg_id, msg);
+						} else {
+							let msg = Message::new();
+							msg.sign_and_return();
+						}
+					}
 				}
 			}
 			Err(err) => {
diff --git a/src/message.rs b/src/message.rs
new file mode 100644
index 0000000..f1514e1
--- /dev/null
+++ b/src/message.rs
@@ -0,0 +1,24 @@
+#[derive(Debug)]
+pub struct Message {
+	lines: Vec<Vec<u8>>,
+}
+
+impl Message {
+	pub fn new() -> Self {
+		Self { lines: Vec::new() }
+	}
+
+	pub fn from_line(line: &[u8]) -> Self {
+		Self {
+			lines: vec![line.to_vec()],
+		}
+	}
+
+	pub fn append_line(&mut self, line: &[u8]) {
+		self.lines.push(line.to_vec())
+	}
+
+	pub fn sign_and_return(&self) {
+		// TODO: sign the message using DKIM and send it to stdout
+	}
+}