diff --git a/src/java/davmail/http/DavGatewayHttpClientFacade.java b/src/java/davmail/http/DavGatewayHttpClientFacade.java
index 4e083fa8..5e6e2418 100644
--- a/src/java/davmail/http/DavGatewayHttpClientFacade.java
+++ b/src/java/davmail/http/DavGatewayHttpClientFacade.java
@@ -41,6 +41,8 @@ import org.apache.log4j.Logger;
 
 import java.io.IOException;
 import java.util.ArrayList;
+import java.net.InetAddress;
+import java.net.UnknownHostException;
 
 /**
  * Create HttpClient instance according to DavGateway Settings
@@ -146,9 +148,16 @@ public final class DavGatewayHttpClientFacade {
                 // detect ntlm authentication (windows domain name in user name)
                 int backslashindex = proxyUser.indexOf('\\');
                 if (backslashindex > 0) {
+                    // get local host name for NTLM authentication
+                    String host;
+                    try {
+                        host = InetAddress.getLocalHost().getHostName();
+                    } catch (UnknownHostException e) {
+                        host = "localhost";
+                    }
                     httpClient.getState().setProxyCredentials(authScope,
                             new NTCredentials(proxyUser.substring(backslashindex + 1),
-                                    proxyPassword, null,
+                                    proxyPassword, host,
                                     proxyUser.substring(0, backslashindex)));
                 } else {
                     httpClient.getState().setProxyCredentials(authScope,