diff --git a/server.js b/server.js
index bc87db9..5668fdf 100644
--- a/server.js
+++ b/server.js
@@ -61,15 +61,36 @@ POP3Server.prototype.listen = function(port, callback){
     var self = this;
     this.socket = net.createServer(function(socket){
       var connection_id = ++self.COUNTER;
-      var cnx = new POP3Connnection(self, socket, connection_id);
+      var connection = new POP3Connnection(self, socket, connection_id);
       socket.on('data', function (data) {
-          self.onData(cnx, data);
+          self.onData(connection, data);
+      });
+      socket.on('end', function (data) {
+          self.onEnd(connection, data);
+      });
+      socket.on('error', function (err) {
+          self.onError(connection, err);
+      });
+    }).listen(port, callback);
+};
+
+POP3Server.prototype.listenSSL = function(port, callback){
+    var self = this;
+    if (!this.options.tls) {
+        return callback(new Error('listenSSL require tls options.'));
+    }
+    this.socket = tls.createServer(this.options.tls, function(socket){
+      var connection_id = ++self.COUNTER;
+      var connection = new POP3Connnection(self, socket, connection_id);
+      connection.secure = true;
+      socket.on('data', function (data) {
+          self.onData(connection, data);
       });
       socket.on('end', function (data) {
-          self.onEnd(cnx, data);
+          self.onEnd(connection, data);
       });
       socket.on('error', function (err) {
-          self.onError(cnx, err);
+          self.onError(connection, err);
       });
     }).listen(port, callback);
 };
@@ -154,11 +175,16 @@ POP3Server.prototype.cmdCAPA = function (connection, params) {
     if (this.authMethods) {
         var methods = [];
         for (var i in this.authMethods) {
-            if (this.authMethods.hasOwnProperty(i))
+            if (this.authMethods.hasOwnProperty(i)) {
                 methods.push(i);
+            }
         }
-        if (methods.length && connection.state == States.AUTHENTICATION)
+        if (methods.length && connection.state == States.AUTHENTICATION) {
             connection.response("SASL " + methods.join(" "));
+        }
+    }
+    if (this.options.tls && !connection.secure && connection.state === States.AUTHENTICATION) {
+        connection.response("STLS");
     }
     connection.response(".");
 }
@@ -185,14 +211,16 @@ POP3Server.prototype.cmdQUIT = function (connection) {
 
 POP3Server.prototype.cmdSTLS = function (connection) {
     var self = this;
-
+    if (connection.secure) {
+      return connection.response("-ERR Command not permitted when TLS active");
+    }
     if (connection.state != States.AUTHENTICATION) {
-      return connection.response("-ERR Only allowed in authentication mode");
+      return connection.response("-ERR Unknown command: STLS");
     }
     if (!this.options.tls) {
-      return connection.response("-ERR invalid command");
+      return connection.response("-ERR Unknown command: STLS");
     }
-    connection.response("+OK begin TLS negotiation");
+    connection.response("+OK Begin TLS negotiation now.");
     connection.socket.removeAllListeners();
     var socketOptions = {
       secureContext: tls.createSecureContext(self.options.tls),
@@ -201,6 +229,7 @@ POP3Server.prototype.cmdSTLS = function (connection) {
     connection.socket = new tls.TLSSocket(connection.socket, socketOptions);
 
     connection.socket.on('secure', function () {
+      connection.secure = true;
       connection.socket.on('data', function (data) {
           self.onData(connection, data);
       });
diff --git a/tests/index.js b/tests/index.js
index c1ee490..91e1d7b 100644
--- a/tests/index.js
+++ b/tests/index.js
@@ -1,10 +1,19 @@
 var expect = require('chai').expect;
 var net = require('net');
+var fs = require('fs');
+var path = require('path');
 var	POP3Client = require('mailx/lib/poplib');
 var	POP3Server = require('../');
 var mailx = require('mailx');
 var mailcomposer = require("mailcomposer");
-var	PORT = 5050;
+
+const	PORT = 11000;
+const SSL_PORT = 9930;
+
+var tlsOptions = {
+  key: fs.readFileSync(path.join(__dirname, '../cert/privatekey.pem')),
+  cert: fs.readFileSync(path.join(__dirname, '../cert/certificate.pem'))
+};
 
 describe('POP3 server', function(){
 	var pop3Server;
@@ -13,52 +22,7 @@ describe('POP3 server', function(){
 	before(function(done){
 		var messageStore = {}, authHandler = {};
 		pop3Server = new POP3Server({
-			tls: {
-				key: '-----BEGIN RSA PRIVATE KEY-----\n' +
-						'MIIEpAIBAAKCAQEA6Z5Qqhw+oWfhtEiMHE32Ht94mwTBpAfjt3vPpX8M7DMCTwHs\n' +
-						'1xcXvQ4lQ3rwreDTOWdoJeEEy7gMxXqH0jw0WfBx+8IIJU69xstOyT7FRFDvA1yT\n' +
-						'RXY2yt9K5s6SKken/ebMfmZR+03ND4UFsDzkz0FfgcjrkXmrMF5Eh5UXX/+9YHeU\n' +
-						'xlp0gMAt+/SumSmgCaysxZLjLpd4uXz+X+JVxsk1ACg1NoEO7lWJC/3WBP7MIcu2\n' +
-						'wVsMd2XegLT0gWYfT1/jsIH64U/mS/SVXC9QhxMl9Yfko2kx1OiYhDxhHs75RJZh\n' +
-						'rNRxgfiwgSb50Gw4NAQaDIxr/DJPdLhgnpY6UQIDAQABAoIBAE+tfzWFjJbgJ0ql\n' +
-						's6Ozs020Sh4U8TZQuonJ4HhBbNbiTtdDgNObPK1uNadeNtgW5fOeIRdKN6iDjVeN\n' +
-						'AuXhQrmqGDYVZ1HSGUfD74sTrZQvRlWPLWtzdhybK6Css41YAyPFo9k4bJ2ZW2b/\n' +
-						'p4EEQ8WsNja9oBpttMU6YYUchGxo1gujN8hmfDdXUQx3k5Xwx4KA68dveJ8GasIt\n' +
-						'd+0Jd/FVwCyyx8HTiF1FF8QZYQeAXxbXJgLBuCsMQJghlcpBEzWkscBR3Ap1U0Zi\n' +
-						'4oat8wrPZGCblaA6rNkRUVbc/+Vw0stnuJ/BLHbPxyBs6w495yBSjBqUWZMvljNz\n' +
-						'm9/aK0ECgYEA9oVIVAd0enjSVIyAZNbw11ElidzdtBkeIJdsxqhmXzeIFZbB39Gd\n' +
-						'bjtAVclVbq5mLsI1j22ER2rHA4Ygkn6vlLghK3ZMPxZa57oJtmL3oP0RvOjE4zRV\n' +
-						'dzKexNGo9gU/x9SQbuyOmuauvAYhXZxeLpv+lEfsZTqqrvPUGeBiEQcCgYEA8poG\n' +
-						'WVnykWuTmCe0bMmvYDsWpAEiZnFLDaKcSbz3O7RMGbPy1cypmqSinIYUpURBT/WY\n' +
-						'wVPAGtjkuTXtd1Cy58m7PqziB7NNWMcsMGj+lWrTPZ6hCHIBcAImKEPpd+Y9vGJX\n' +
-						'oatFJguqAGOz7rigBq6iPfeQOCWpmprNAuah++cCgYB1gcybOT59TnA7mwlsh8Qf\n' +
-						'bm+tSllnin2A3Y0dGJJLmsXEPKtHS7x2Gcot2h1d98V/TlWHe5WNEUmx1VJbYgXB\n' +
-						'pw8wj2ACxl4ojNYqWPxegaLd4DpRbtW6Tqe9e47FTnU7hIggR6QmFAWAXI+09l8y\n' +
-						'amssNShqjE9lu5YDi6BTKwKBgQCuIlKGViLfsKjrYSyHnajNWPxiUhIgGBf4PI0T\n' +
-						'/Jg1ea/aDykxv0rKHnw9/5vYGIsM2st/kR7l5mMecg/2Qa145HsLfMptHo1ZOPWF\n' +
-						'9gcuttPTegY6aqKPhGthIYX2MwSDMM+X0ri6m0q2JtqjclAjG7yG4CjbtGTt/UlE\n' +
-						'WMlSZwKBgQDslGeLUnkW0bsV5EG3AKRUyPKz/6DVNuxaIRRhOeWVKV101claqXAT\n' +
-						'wXOpdKrvkjZbT4AzcNrlGtRl3l7dEVXTu+dN7/ZieJRu7zaStlAQZkIyP9O3DdQ3\n' +
-						'rIcetQpfrJ1cAqz6Ng0pD0mh77vQ13WG1BBmDFa2A9BuzLoBituf4g==\n' +
-						'-----END RSA PRIVATE KEY-----',
-				cert: '-----BEGIN CERTIFICATE-----\n' +
-						'MIICpDCCAYwCCQCuVLVKVTXnAjANBgkqhkiG9w0BAQsFADAUMRIwEAYDVQQDEwls\n' +
-						'b2NhbGhvc3QwHhcNMTUwMjEyMTEzMjU4WhcNMjUwMjA5MTEzMjU4WjAUMRIwEAYD\n' +
-						'VQQDEwlsb2NhbGhvc3QwggEiMA0GCSqGSIb3DQEBAQUAA4IBDwAwggEKAoIBAQDp\n' +
-						'nlCqHD6hZ+G0SIwcTfYe33ibBMGkB+O3e8+lfwzsMwJPAezXFxe9DiVDevCt4NM5\n' +
-						'Z2gl4QTLuAzFeofSPDRZ8HH7wgglTr3Gy07JPsVEUO8DXJNFdjbK30rmzpIqR6f9\n' +
-						'5sx+ZlH7Tc0PhQWwPOTPQV+ByOuReaswXkSHlRdf/71gd5TGWnSAwC379K6ZKaAJ\n' +
-						'rKzFkuMul3i5fP5f4lXGyTUAKDU2gQ7uVYkL/dYE/swhy7bBWwx3Zd6AtPSBZh9P\n' +
-						'X+OwgfrhT+ZL9JVcL1CHEyX1h+SjaTHU6JiEPGEezvlElmGs1HGB+LCBJvnQbDg0\n' +
-						'BBoMjGv8Mk90uGCeljpRAgMBAAEwDQYJKoZIhvcNAQELBQADggEBABXm8GPdY0sc\n' +
-						'mMUFlgDqFzcevjdGDce0QfboR+M7WDdm512Jz2SbRTgZD/4na42ThODOZz9z1AcM\n' +
-						'zLgx2ZNZzVhBz0odCU4JVhOCEks/OzSyKeGwjIb4JAY7dh+Kju1+6MNfQJ4r1Hza\n' +
-						'SVXH0+JlpJDaJ73NQ2JyfqELmJ1mTcptkA/N6rQWhlzycTBSlfogwf9xawgVPATP\n' +
-						'4AuwgjHl12JI2HVVs1gu65Y3slvaHRCr0B4+Kg1GYNLLcbFcK+NEHrHmPxy9TnTh\n' +
-						'Zwp1dsNQU+Xkylz8IUANWSLHYZOMtN2e5SKIdwTtl5C8YxveuY8YKb1gDExnMraT\n' +
-						'VGXQDqPleug=\n' +
-						'-----END CERTIFICATE-----'		
-			},
+			tls: tlsOptions,
 			auth: function(user, checkPassword) {
         var password = false;
         if (user === 'jdoe' || user === 'jdoe2') {
@@ -96,7 +60,12 @@ describe('POP3 server', function(){
 				}
 			}
 		});
-		pop3Server.listen(PORT, done);
+		pop3Server.listen(PORT, function(err) {
+			if (err) {
+				return done(err);
+			}
+			pop3Server.listenSSL(SSL_PORT, done);
+		});
 	});
 
 	it('It should be listening on the appropriate port', function(done){
@@ -118,6 +87,7 @@ describe('POP3 server', function(){
 			return done();
 		});
 	});
+
 	it('Should support QUIT command', function(done){
 		var client = new POP3Client(PORT, 'localhost');
 		client.connect(function(err, raw) {
@@ -134,6 +104,27 @@ describe('POP3 server', function(){
 		});
 	});
 
+	it('Should support STLS command', function(done){
+		var client = new POP3Client(PORT, 'localhost', {ignoretlserrs: true});
+		client.connect(function(err, raw) {
+			if (err) {
+				return done(err);
+			}
+			client.stls(function(err, raw) {
+				if (err) {
+					return done(err);
+				}
+				client.quit(function(err, raw) {
+					if (err) {
+						return done(err);
+					}
+					expect(raw).equal('+OK POP3 Server signing off\r\n');
+					done();
+				});
+			});
+		});
+	});
+
 	it('Should Accept valid Login credentials via USER-PASS sequence', function(done){
 		var client = new POP3Client(PORT, 'localhost');
 		client.connect(function(err, raw) {