diff --git a/hsarback/src/de/hsadmin/autoconfig/AutoconfigAutodiscoverServlet.java b/hsarback/src/de/hsadmin/autoconfig/AutoconfigAutodiscoverServlet.java
index 69fde6a..c9301c0 100644
--- a/hsarback/src/de/hsadmin/autoconfig/AutoconfigAutodiscoverServlet.java
+++ b/hsarback/src/de/hsadmin/autoconfig/AutoconfigAutodiscoverServlet.java
@@ -5,6 +5,7 @@ import java.io.IOException;
 import javax.persistence.EntityManager;
 import javax.persistence.Query;
 import javax.servlet.ServletException;
+import javax.servlet.ServletInputStream;
 import javax.servlet.http.HttpServlet;
 import javax.servlet.http.HttpServletRequest;
 import javax.servlet.http.HttpServletResponse;
@@ -21,10 +22,11 @@ import org.apache.commons.httpclient.HttpStatus;
 import org.w3c.dom.DOMException;
 import org.w3c.dom.Document;
 import org.w3c.dom.Element;
+import org.w3c.dom.NodeList;
+import org.xml.sax.SAXException;
 
 import de.hsadmin.core.model.HSAdminException;
 import de.hsadmin.core.model.Transaction;
-import de.hsadmin.core.util.IPv6Trick;
 import de.hsadmin.mods.email.EMailAddress;
 import de.hsadmin.mods.user.UnixUser;
 
@@ -92,14 +94,98 @@ public class AutoconfigAutodiscoverServlet extends HttpServlet {
 	 */
 	@Override
 	protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
-		final String remoteAddr = req.getRemoteAddr();
-		if (!IPv6Trick.isKnownRemote(remoteAddr)) {
-			resp.sendError(HttpStatus.SC_UNAUTHORIZED);
-			return;
+		final ServletInputStream xmlInputStream = req.getInputStream();
+		try {
+			String emailAddr = "";
+			final DocumentBuilderFactory builderFactory = DocumentBuilderFactory.newInstance();
+			DocumentBuilder builder = builderFactory.newDocumentBuilder();
+			final Document requestDocument = builder.parse(xmlInputStream);
+			final Element documentElement = requestDocument.getDocumentElement();
+			documentElement.normalize();
+			final NodeList emailAddressNodeList = documentElement.getElementsByTagName("EMailAddress");
+			if (emailAddressNodeList.getLength() == 1) {
+				emailAddr = emailAddressNodeList.item(0).getTextContent().trim();
+			}
+			final String[] addrParts = emailAddr.split("@");
+			if (addrParts.length != 2) {
+				resp.sendError(HttpStatus.SC_BAD_REQUEST);
+				return;
+			}
+			String uniqueMailbox = null;
+			try {
+				uniqueMailbox = getUniqueMailbox(emailAddr);
+			} catch (HSAdminException e) {
+				throw new ServletException(e);
+			}
+			final Document document = buildAutodiscoverDocument(builderFactory, uniqueMailbox);
+			serializeDocument(document, resp);
+		} catch (ParserConfigurationException e) {
+			throw new ServletException(e);
+		} catch (SAXException e) {
+			throw new ServletException(e);
 		}
 	}
+
+//	public static void main(String[] args) {
+//		final DocumentBuilderFactory builderFactory = DocumentBuilderFactory.newInstance();
+//		final String mbox = "xyz00-test";
+//		try {
+//			final Document document = buildAutodiscoverDocument(builderFactory, mbox);
+//			final TransformerFactory transformerFactory = TransformerFactory.newInstance();
+//			final Transformer transformer = transformerFactory.newTransformer();
+//			transformer.transform(new DOMSource(document), new StreamResult(System.out));
+//		} catch (ParserConfigurationException e) {
+//			// TODO Auto-generated catch block
+//			e.printStackTrace();
+//		} catch (TransformerException e) {
+//			// TODO Auto-generated catch block
+//			e.printStackTrace();
+//		}
+//	}
 	
-	private Element appendElementWithAttribute(final Document document, final Element parent,
+	private static Document buildAutodiscoverDocument(final DocumentBuilderFactory builderFactory, String uniqueMailbox)
+			throws ParserConfigurationException {
+		DocumentBuilder builder;
+		final String pacName = uniqueMailbox.substring(0, 5);
+		final String pacDomain = pacName + ".hostsharing.net"; 
+		final String userName = uniqueMailbox;
+		builder = builderFactory.newDocumentBuilder();
+		final Document document = builder.newDocument();
+		final Element autodiscover = document.createElementNS("http://schemas.microsoft.com/exchange/autodiscover/responseschema/2006", "Autodiscover");
+		document.appendChild(autodiscover);
+		final Element response = document.createElementNS("http://schemas.microsoft.com/exchange/autodiscover/outlook/responseschema/2006a", "Response");
+		autodiscover.appendChild(response);
+		final Element user = document.createElement("User");
+		response.appendChild(user);
+		appendElementWithText(document, user, "DisplayName", pacDomain);
+		final Element account = document.createElement("Account");
+		response.appendChild(account);
+		appendElementWithText(document, account, "AccountType", "email");
+		appendElementWithText(document, account, "Action", "settings");
+		final Element protocolIMAP = document.createElement("Protocol");
+		account.appendChild(protocolIMAP);
+		appendElementWithText(document, protocolIMAP, "Type", "IMAP");
+		appendElementWithText(document, protocolIMAP, "Server", pacDomain);
+		appendElementWithText(document, protocolIMAP, "Port", "993");
+		appendElementWithText(document, protocolIMAP, "DomainRequired", "off");
+		appendElementWithText(document, protocolIMAP, "SPA", "off");
+		appendElementWithText(document, protocolIMAP, "SSL", "on");
+		appendElementWithText(document, protocolIMAP, "AuthRequired", "on");
+		appendElementWithText(document, protocolIMAP, "LoginName", userName);
+		final Element protocolSMTP = document.createElement("Protocol");
+		account.appendChild(protocolSMTP);
+		appendElementWithText(document, protocolSMTP, "Type", "SMTP");
+		appendElementWithText(document, protocolSMTP, "Server", pacDomain);
+		appendElementWithText(document, protocolSMTP, "Port", "465");
+		appendElementWithText(document, protocolSMTP, "DomainRequired", "off");
+		appendElementWithText(document, protocolSMTP, "SPA", "off");
+		appendElementWithText(document, protocolSMTP, "SSL", "on");
+		appendElementWithText(document, protocolSMTP, "AuthRequired", "on");
+		appendElementWithText(document, protocolSMTP, "LoginName", userName);
+		return document;
+	}
+	
+	private static Element appendElementWithAttribute(final Document document, final Element parent,
 			final String childElementName, final String attributeName, final String attributeValue) {
 		final Element child = document.createElement(childElementName);
 		child.setAttribute(attributeName, attributeValue);
@@ -107,7 +193,7 @@ public class AutoconfigAutodiscoverServlet extends HttpServlet {
 		return child;
 	}
 	
-	private Element appendElementWithText(final Document document, final Element parent, 
+	private static Element appendElementWithText(final Document document, final Element parent, 
 			final String childElementName, final String text) {
 		final Element child = document.createElement(childElementName);
 		parent.appendChild(child);
@@ -115,12 +201,12 @@ public class AutoconfigAutodiscoverServlet extends HttpServlet {
 		return child;
 	}
 	
-	private void serializeDocument(final Document document, final HttpServletResponse resp)
+	private static void serializeDocument(final Document document, final HttpServletResponse resp)
 			throws ServletException {
 		resp.setContentType("text/xml");
 		try {
-			TransformerFactory transformerFactory = TransformerFactory.newInstance();
-			Transformer transformer = transformerFactory.newTransformer();
+			final TransformerFactory transformerFactory = TransformerFactory.newInstance();
+			final Transformer transformer = transformerFactory.newTransformer();
 			transformer.transform(new DOMSource(document), new StreamResult(resp.getOutputStream()));
 		} catch (TransformerException e) {
 			throw new ServletException(e);