diff --git a/lib/server.js b/lib/server.js
index 4288c24..fc57c42 100644
--- a/lib/server.js
+++ b/lib/server.js
@@ -307,6 +307,11 @@ SMTPServerConnection.prototype._onCommand = function(command, payload){
             this._onCommandSTARTTLS();
             break;
 
+        // Get info from proxy server
+        case "XCLIENT":
+            this._onCommandXCLIENT(payload.toString("utf-8").trim());
+            break;
+
         // No operation
         case "NOOP":
             this._onCommandNOOP();
@@ -314,7 +319,7 @@ SMTPServerConnection.prototype._onCommand = function(command, payload){
 
         // Display an error on anything else
         default:
-            this.client.send("502 5.5.2 Error: command not recognized");
+            // this.client.send("502 5.5.2 Error: command not recognized");
     }
 };
 
@@ -624,6 +629,21 @@ SMTPServerConnection.prototype._onCommandEHLO = function(host){
     }).join("\r\n"));
 };
 
+/**
+ * <p>No operation. Just returns OK.</p>
+ */
+SMTPServerConnection.prototype._onCommandXCLIENT = function(attributes){
+    var attr;
+    var pairs = attributes.split(" ");
+    var attributes_dict = {};
+    for (var i in pairs) {
+        attr = pairs[i].split("=");
+        attributes_dict[attr[0]] = attr[1];
+    }
+    this.envelope.xclient = attributes_dict;
+    this.client.send("220 success");
+};
+
 /**
  * <p>No operation. Just returns OK.</p>
  */
diff --git a/test/server.js b/test/server.js
index a3dd2ec..53cea43 100644
--- a/test/server.js
+++ b/test/server.js
@@ -207,6 +207,47 @@ exports["EHLO setting"] = {
     }
 };
 
+exports["XCLIENT extension"] = {
+    setUp: function (callback) {
+
+        this.smtp = new simplesmtp.createServer({disableDNSValidation: true});
+        this.smtp.listen(PORT_NUMBER, function(err){
+            if(err){
+                throw err;
+            }else{
+                callback();
+            }
+        });
+
+    },
+    tearDown: function (callback) {
+        this.smtp.end(callback);
+    },
+    "correct response": function(test) {
+        runClientMockup(PORT_NUMBER, "localhost", ["EHLO foo", "XCLIENT ADDR=127.0.0.2"], function(resp){
+            test.equal("220 success",resp.toString("utf-8").trim());
+            test.done();
+        });
+    },
+    "correct parse and save attributes": function(test) {
+        var messages = [
+            "EHLO foo",
+            "XCLIENT ADDR=127.0.0.1 LOGIN=user@example.org",
+            "EHLO foo",
+            "MAIL FROM:<john.doe@example.org>",
+            "RCPT TO:<jane.doe@example.org>",
+            "DATA"
+        ]
+        this.smtp.on("startData", function(envelope){
+            test.ok("xclient" in envelope);
+            test.equal(envelope.xclient.ADDR, "127.0.0.1");
+            test.equal(envelope.xclient.LOGIN, "user@example.org");
+            test.done();
+        });
+        runClientMockup(PORT_NUMBER, "localhost", messages);
+    }
+};
+
 exports["Client disconnect"] = {
 
     "Client disconnect": function(test){