diff --git a/src/java/davmail/exchange/ExchangeSession.java b/src/java/davmail/exchange/ExchangeSession.java
index 3614001d..9c400c30 100644
--- a/src/java/davmail/exchange/ExchangeSession.java
+++ b/src/java/davmail/exchange/ExchangeSession.java
@@ -813,6 +813,42 @@ public abstract class ExchangeSession {
         return messages;
     }
 
+    protected enum Operator {
+        Or, And, Not, IsEqualTo
+    }
+
+    protected abstract static class Condition {
+        public abstract void appendTo(StringBuilder buffer);
+    }
+
+    protected abstract class AttributeCondition extends Condition {
+        protected String attributeName;
+        protected Operator operator;
+        protected String value;
+
+        protected AttributeCondition(String attributeName, Operator operator, String value) {
+            this.attributeName = attributeName;
+            this.operator = operator;
+            this.value = value;
+        }
+    }
+
+    protected abstract class MultiCondition extends Condition {
+        protected Operator operator;
+        protected Condition[] conditions;
+
+        protected MultiCondition(Operator operator, Condition... condition) {
+            this.operator = operator;
+            conditions = condition;
+        }
+    }
+
+    protected abstract Condition and(Condition... condition);
+
+    protected abstract Condition or(Condition... condition);
+
+    protected abstract AttributeCondition equals(String attributeName, String value);
+
     /**
      * Search folders under given folder.
      *
@@ -822,7 +858,8 @@ public abstract class ExchangeSession {
      * @throws IOException on error
      */
     public List<Folder> getSubFolders(String folderName, boolean recursive) throws IOException {
-        return getSubFolders(folderName, "(\"DAV:contentclass\"='urn:content-classes:mailfolder' OR \"DAV:contentclass\"='urn:content-classes:folder')", recursive);
+        // "(\"DAV:contentclass\"='urn:content-classes:mailfolder' OR \"DAV:contentclass\"='urn:content-classes:folder')"
+        return getSubFolders(folderName, equals("folderclass", "IPF.Note"), recursive);
     }
 
     /**
@@ -834,19 +871,20 @@ public abstract class ExchangeSession {
      * @throws IOException on error
      */
     public List<Folder> getSubCalendarFolders(String folderName, boolean recursive) throws IOException {
-        return getSubFolders(folderName, "\"DAV:contentclass\"='urn:content-classes:calendarfolder'", recursive);
+        // "\"DAV:contentclass\"='urn:content-classes:calendarfolder'"
+        return getSubFolders(folderName, equals("folderclass", "IPF.Appointment"), recursive);
     }
 
     /**
      * Search folders under given folder matching filter.
      *
      * @param folderName Exchange folder name
-     * @param filter     search filter
+     * @param condition  search filter
      * @param recursive  deep search if true
      * @return list of folders
      * @throws IOException on error
      */
-    public abstract List<Folder> getSubFolders(String folderName, String filter, boolean recursive) throws IOException;
+    public abstract List<Folder> getSubFolders(String folderName, Condition condition, boolean recursive) throws IOException;
 
     /**
      * Delete oldest messages in trash.
@@ -1159,9 +1197,9 @@ public abstract class ExchangeSession {
         public String folderPath;
 
         /**
-         * Folder content class.
+         * Folder class (PR_CONTAINER_CLASS).
          */
-        public String contentClass;
+        public String folderClass;
         /**
          * Folder unread message count.
          */
@@ -1305,7 +1343,7 @@ public abstract class ExchangeSession {
          * @return true if this is a calendar folder
          */
         public boolean isCalendar() {
-            return "urn:content-classes:calendarfolder".equals(contentClass);
+            return "IPF.Appointment".equals(folderClass);
         }
 
         /**
@@ -1314,7 +1352,7 @@ public abstract class ExchangeSession {
          * @return true if this is a calendar folder
          */
         public boolean isContact() {
-            return "urn:content-classes:contactfolder".equals(contentClass);
+            return "IPF.Contact".equals(folderClass);
         }
 
         /**
diff --git a/src/java/davmail/exchange/dav/DavExchangeSession.java b/src/java/davmail/exchange/dav/DavExchangeSession.java
index c2d4bc31..257bd77a 100644
--- a/src/java/davmail/exchange/dav/DavExchangeSession.java
+++ b/src/java/davmail/exchange/dav/DavExchangeSession.java
@@ -37,7 +37,9 @@ import java.io.IOException;
 import java.io.InputStreamReader;
 import java.net.URL;
 import java.util.ArrayList;
+import java.util.HashMap;
 import java.util.List;
+import java.util.Map;
 
 /**
  * Webdav Exchange adapter.
@@ -168,16 +170,79 @@ public class DavExchangeSession extends ExchangeSession {
         }
     }
 
+    protected class MultiCondition extends ExchangeSession.MultiCondition {
+        protected MultiCondition(Operator operator, Condition... condition) {
+            super(operator, condition);
+        }
+
+        @Override
+        public void appendTo(StringBuilder buffer) {
+            boolean first = true;
+            buffer.append('(');
+            for (Condition condition : conditions) {
+                if (first) {
+                    first = false;
+                } else {
+                    buffer.append(' ').append(operator).append(' ');
+                }
+                condition.appendTo(buffer);
+            }
+            buffer.append(')');
+        }
+    }
+
+    static final Map<String, String> attributeMap = new HashMap<String, String>();
+
+    static {
+        attributeMap.put("folderclass", "http://schemas.microsoft.com/exchange/outlookfolderclass");
+        attributeMap.put("contentclass", "DAV:contentclass");
+    }
+
+    static final Map<Operator, String> operatorMap = new HashMap<Operator, String>();
+
+    static {
+        operatorMap.put(Operator.IsEqualTo, "=");
+    }
+
+    protected class AttributeCondition extends ExchangeSession.AttributeCondition {
+        protected AttributeCondition(String attributeName, Operator operator, String value) {
+            super(attributeName, operator, value);
+        }
+
+        @Override
+        public void appendTo(StringBuilder buffer) {
+            buffer.append('"').append(attributeMap.get(attributeName)).append('"');
+            buffer.append(operatorMap.get(operator));
+            buffer.append('\'').append(value).append('\'');
+        }
+    }
+
+    @Override
+    protected Condition and(Condition... condition) {
+        return new MultiCondition(Operator.And, condition);
+    }
+
+    @Override
+    protected Condition or(Condition... condition) {
+        return new MultiCondition(Operator.Or, condition);
+    }
+
+    @Override
+    protected AttributeCondition equals(String attributeName, String value) {
+        return new AttributeCondition(attributeName, Operator.IsEqualTo, value);
+    }
+
+
     protected Folder buildFolder(MultiStatusResponse entity) throws IOException {
         String href = URIUtil.decode(entity.getHref());
         Folder folder = new Folder();
         DavPropertySet properties = entity.getProperties(HttpStatus.SC_OK);
-        folder.contentClass = getPropertyIfExists(properties, "contentclass", DAV);
+        folder.folderClass = getPropertyIfExists(properties, "outlookfolderclass", SCHEMAS_EXCHANGE);
         folder.hasChildren = "1".equals(getPropertyIfExists(properties, "hassubs", DAV));
         folder.noInferiors = "1".equals(getPropertyIfExists(properties, "nosubs", DAV));
         folder.unreadCount = getIntPropertyIfExists(properties, "unreadcount", URN_SCHEMAS_HTTPMAIL);
         folder.ctag = getPropertyIfExists(properties, "contenttag", Namespace.getNamespace("http://schemas.microsoft.com/repl/"));
-        folder.etag = getPropertyIfExists(properties, "resourcetag", Namespace.getNamespace("http://schemas.microsoft.com/repl/"));
+        folder.etag = getPropertyIfExists(properties, "x30080040", SCHEMAS_MAPI_PROPTAG);
 
         // replace well known folder names
         if (href.startsWith(inboxUrl)) {
@@ -230,15 +295,17 @@ public class DavExchangeSession extends ExchangeSession {
      * @inheritDoc
      */
     @Override
-    public List<Folder> getSubFolders(String folderName, String filter, boolean recursive) throws IOException {
+    public List<Folder> getSubFolders(String folderName, Condition condition, boolean recursive) throws IOException {
         String mode = recursive ? "DEEP" : "SHALLOW";
         List<Folder> folders = new ArrayList<Folder>();
         StringBuilder searchRequest = new StringBuilder();
-        searchRequest.append("Select \"DAV:nosubs\", \"DAV:hassubs\"," +
+        searchRequest.append("Select \"DAV:nosubs\", \"DAV:hassubs\", \"http://schemas.microsoft.com/exchange/outlookfolderclass\", " +
+                "\"http://schemas.microsoft.com/repl/contenttag\", \"http://schemas.microsoft.com/mapi/proptag/x30080040\", " +
                 "\"urn:schemas:httpmail:unreadcount\" FROM Scope('").append(mode).append(" TRAVERSAL OF \"").append(getFolderPath(folderName)).append("\"')\n" +
                 " WHERE \"DAV:ishidden\" = False AND \"DAV:isfolder\" = True \n");
-        if (filter != null && filter.length() > 0) {
-            searchRequest.append("                      AND ").append(filter);
+        if (condition != null) {
+            searchRequest.append("                      AND ");
+            condition.appendTo(searchRequest);
         }
         MultiStatusResponse[] responses = DavGatewayHttpClientFacade.executeSearchMethod(
                 httpClient, URIUtil.encodePath(getFolderPath(folderName)), searchRequest.toString());
@@ -248,5 +315,5 @@ public class DavExchangeSession extends ExchangeSession {
         }
         return folders;
     }
-    
+
 }
diff --git a/src/java/davmail/exchange/ews/EWSMethod.java b/src/java/davmail/exchange/ews/EWSMethod.java
index c53ee44f..d99d6595 100644
--- a/src/java/davmail/exchange/ews/EWSMethod.java
+++ b/src/java/davmail/exchange/ews/EWSMethod.java
@@ -133,9 +133,11 @@ public abstract class EWSMethod extends PostMethod {
             baseShape.write(writer);
             if (additionalProperties != null) {
                 writer.write("<t:AdditionalProperties>");
+                StringBuilder buffer = new StringBuilder();
                 for (FieldURI fieldURI : additionalProperties) {
-                    fieldURI.write(writer);
+                    fieldURI.appendTo(buffer);
                 }
+                writer.write(buffer.toString());
                 writer.write("</t:AdditionalProperties>");
             }
             if (includeMimeContent) {
@@ -194,7 +196,9 @@ public abstract class EWSMethod extends PostMethod {
     protected void writeRestriction(Writer writer) throws IOException {
         if (searchExpression != null) {
             writer.write("<m:Restriction>");
-            searchExpression.write(writer);
+            StringBuilder buffer = new StringBuilder();
+            searchExpression.appendTo(buffer);
+            writer.write(buffer.toString());
             writer.write("</m:Restriction>");
         }
     }
@@ -281,6 +285,15 @@ public abstract class EWSMethod extends PostMethod {
             writer.write(type);
             writer.write(">");
         }
+
+        public int getInt(String key) {
+            int result = 0;
+            String value = get(key);
+            if (value != null && value.length() > 0) {
+                result = Integer.parseInt(value);
+            }
+            return result;
+        }
     }
 
     public List<Item> getResponseItems() {
diff --git a/src/java/davmail/exchange/ews/EwsExchangeSession.java b/src/java/davmail/exchange/ews/EwsExchangeSession.java
index cbaa44ba..4331d2f0 100644
--- a/src/java/davmail/exchange/ews/EwsExchangeSession.java
+++ b/src/java/davmail/exchange/ews/EwsExchangeSession.java
@@ -18,12 +18,20 @@
  */
 package davmail.exchange.ews;
 
+import davmail.exception.DavMailAuthenticationException;
 import davmail.exception.DavMailException;
 import davmail.exchange.ExchangeSession;
+import davmail.http.DavGatewayHttpClientFacade;
+import davmail.util.StringUtil;
 import org.apache.commons.httpclient.HttpMethod;
+import org.apache.commons.httpclient.HttpStatus;
+import org.apache.commons.httpclient.methods.HeadMethod;
 
 import java.io.IOException;
+import java.util.ArrayList;
+import java.util.HashMap;
 import java.util.List;
+import java.util.Map;
 
 /**
  * EWS Exchange adapter.
@@ -31,7 +39,7 @@ import java.util.List;
  */
 public class EwsExchangeSession extends ExchangeSession {
 
-    protected class EwsFolder extends Folder {
+    protected class Folder extends ExchangeSession.Folder {
         public FolderId folderId;
     }
 
@@ -45,39 +53,147 @@ public class EwsExchangeSession extends ExchangeSession {
     @Override
     protected void buildSessionInfo(HttpMethod method) throws DavMailException {
         // nothing to do, mailPath not used in EWS mode
+        // check EWS access
+        HttpMethod headMethod = new HeadMethod("/ews/services.wsdl");
+        try {
+            headMethod = DavGatewayHttpClientFacade.executeFollowRedirects(httpClient, headMethod);
+            if (headMethod.getStatusCode() != HttpStatus.SC_OK) {
+                throw DavGatewayHttpClientFacade.buildHttpException(headMethod);
+            }
+        } catch (IOException e) {
+            LOGGER.error(e.getMessage());
+            throw new DavMailAuthenticationException("EXCEPTION_EWS_NOT_AVAILABLE");
+        } finally {
+            headMethod.releaseConnection();
+        }
+    }
+
+    protected class MultiCondition extends ExchangeSession.MultiCondition implements SearchExpression {
+        protected MultiCondition(Operator operator, Condition... condition) {
+            super(operator, condition);
+        }
+
+        @Override
+        public void appendTo(StringBuilder buffer) {
+            buffer.append("<t:").append(operator.toString()).append('>');
+
+            for (Condition condition : conditions) {
+                condition.appendTo(buffer);
+            }
+
+            buffer.append("</t:").append(operator.toString()).append('>');
+        }
+    }
+
+    static final Map<String, FieldURI> attributeMap = new HashMap<String, FieldURI>();
+
+    static {
+        attributeMap.put("folderclass", ExtendedFieldURI.PR_CONTAINER_CLASS);
+    }
+
+    protected class AttributeCondition extends ExchangeSession.AttributeCondition implements SearchExpression {
+        protected AttributeCondition(String attributeName, Operator operator, String value) {
+            super(attributeName, operator, value);
+        }
+
+        @Override
+        public void appendTo(StringBuilder buffer) {
+            buffer.append("<t:").append(operator.toString()).append('>');
+            attributeMap.get(attributeName).appendTo(buffer);
+
+            buffer.append("<t:FieldURIOrConstant><t:Constant Value=\"");
+            buffer.append(StringUtil.xmlEncode(value));
+            buffer.append("\"/></t:FieldURIOrConstant>");
+
+            buffer.append("</t:").append(operator.toString()).append('>');
+        }
+    }
+
+    @Override
+    protected Condition and(Condition... condition) {
+        return new MultiCondition(Operator.And, condition);
+    }
+
+    @Override
+    protected Condition or(Condition... condition) {
+        return new MultiCondition(Operator.Or, condition);
+    }
+
+    @Override
+    protected AttributeCondition equals(String attributeName, String value) {
+        return new AttributeCondition(attributeName, Operator.IsEqualTo, value);
+    }
+
+    protected Folder buildFolder(EWSMethod.Item item) {
+        Folder folder = new Folder();
+        folder.folderId = new FolderId(item.get("FolderId"));
+        folder.etag = item.get(ExtendedFieldURI.PR_LAST_MODIFICATION_TIME.getPropertyTag());
+        // TODO: implement ctag
+        folder.ctag = String.valueOf(System.currentTimeMillis());
+        // TODO: implement contentClass, noInferiors
+        folder.unreadCount = item.getInt("UnreadCount");
+        folder.hasChildren = item.getInt("ChildFolderCount") != 0;
+        // noInferiors not implemented
+        return folder;
     }
 
     /**
      * @inheritDoc
      */
     @Override
-    public List<Folder> getSubFolders(String folderName, String filter, boolean recursive) throws IOException {
-        // TODO
-        throw new UnsupportedOperationException();
+    public List<ExchangeSession.Folder> getSubFolders(String folderPath, Condition condition, boolean recursive) throws IOException {
+
+        List<ExchangeSession.Folder> folders = new ArrayList<ExchangeSession.Folder>();
+        appendSubFolders(folders, folderPath, getFolderId(folderPath), condition, recursive);
+        return folders;
+    }
+
+    protected void appendSubFolders(List<ExchangeSession.Folder> folders,
+                                    String parentFolderPath, FolderId parentFolderId,
+                                    Condition condition, boolean recursive) throws IOException {
+        FindFolderMethod findFolderMethod = new FindFolderMethod(FolderQueryTraversal.SHALLOW, BaseShape.ALL_PROPERTIES, parentFolderId);
+        findFolderMethod.setSearchExpression((SearchExpression) condition);
+        findFolderMethod.addAdditionalProperty(ExtendedFieldURI.PR_URL_COMP_NAME);
+        findFolderMethod.addAdditionalProperty(ExtendedFieldURI.PR_LAST_MODIFICATION_TIME);
+        try {
+            httpClient.executeMethod(findFolderMethod);
+        } finally {
+            findFolderMethod.releaseConnection();
+        }
+        for (EWSMethod.Item item : findFolderMethod.getResponseItems()) {
+            Folder folder = buildFolder(item);
+            if (parentFolderPath.length() > 0) {
+                folder.folderPath = parentFolderPath + '/' + item.get(ExtendedFieldURI.PR_URL_COMP_NAME.getPropertyTag());
+            } else {
+                folder.folderPath = item.get(ExtendedFieldURI.PR_URL_COMP_NAME.getPropertyTag());
+            }
+            folders.add(folder);
+            if (recursive && folder.hasChildren) {
+                appendSubFolders(folders, folder.folderPath, folder.folderId, condition, recursive);
+            }
+        }
     }
 
     /**
      * @inheritDoc
      */
     @Override
-    public Folder getFolder(String folderPath) throws IOException {
+    public ExchangeSession.Folder getFolder(String folderPath) throws IOException {
         GetFolderMethod getFolderMethod = new GetFolderMethod(BaseShape.ALL_PROPERTIES, getFolderId(folderPath));
         getFolderMethod.addAdditionalProperty(ExtendedFieldURI.PR_URL_COMP_NAME);
         getFolderMethod.addAdditionalProperty(ExtendedFieldURI.PR_LAST_MODIFICATION_TIME);
         //getFolderMethod.addAdditionalProperty(new ExtendedFieldURI("0x65E2", ExtendedFieldURI.PropertyType.Binary));
         //getFolderMethod.addAdditionalProperty(new ExtendedFieldURI("00062040-0000-0000-C000-000000000046", 0x8A23, ExtendedFieldURI.PropertyType.SystemTime));
-
-        httpClient.executeMethod(getFolderMethod);
+        try {
+            httpClient.executeMethod(getFolderMethod);
+        } finally {
+            getFolderMethod.releaseConnection();
+        }
         EWSMethod.Item item = getFolderMethod.getResponseItem();
-        EwsFolder folder = null;
+        Folder folder = null;
         if (item != null) {
-            folder = new EwsFolder();
-            folder.folderId = new FolderId(item.get("FolderId"));
-            folder.folderName = folderPath;
-            folder.etag = item.get(ExtendedFieldURI.PR_LAST_MODIFICATION_TIME.getPropertyTag());
-            // TODO: implement ctag
-            folder.ctag = String.valueOf(System.currentTimeMillis());
-            // TODO: implement contentClass, unreadCount, hasChildren, noInferiors
+            folder = buildFolder(item);
+            folder.folderPath = folderPath;
         }
         return folder;
     }
@@ -95,7 +211,7 @@ public class EwsExchangeSession extends ExchangeSession {
                 currentFolderId = DistinguishedFolderId.DRAFTS;
             } else if ("Trash".equals(folderName)) {
                 currentFolderId = DistinguishedFolderId.DELETEDITEMS;
-            } else {
+            } else if (folderName.length() > 0) {
                 currentFolderId = getSubFolderByName(currentFolderId, folderName);
             }
         }
@@ -110,9 +226,14 @@ public class EwsExchangeSession extends ExchangeSession {
                 new TwoOperandExpression(TwoOperandExpression.Operator.IsEqualTo,
                         ExtendedFieldURI.PR_URL_COMP_NAME, folderName)
         );
-        httpClient.executeMethod(findFolderMethod);
+        try {
+            httpClient.executeMethod(findFolderMethod);
+        } finally {
+            findFolderMethod.releaseConnection();
+        }
         EWSMethod.Item item = findFolderMethod.getResponseItem();
-        return new FolderId(item.get("Id"));
+        // TODO: handle not found error
+        return new FolderId(item.get("FolderId"));
     }
 
 }
diff --git a/src/java/davmail/exchange/ews/ExtendedFieldURI.java b/src/java/davmail/exchange/ews/ExtendedFieldURI.java
index af4dd74a..7560a626 100644
--- a/src/java/davmail/exchange/ews/ExtendedFieldURI.java
+++ b/src/java/davmail/exchange/ews/ExtendedFieldURI.java
@@ -51,26 +51,18 @@ public class ExtendedFieldURI implements FieldURI {
         return propertyTag;
     }
 
-    public void write(Writer writer) throws IOException {
-        writer.write("<t:ExtendedFieldURI ");
+    public void appendTo(StringBuilder buffer) {
+        buffer.append("<t:ExtendedFieldURI ");
         if (propertyTag != null) {
-            writer.write("PropertyTag=\"");
-            writer.write(propertyTag);
-            writer.write("\" ");
+            buffer.append("PropertyTag=\"").append(propertyTag).append("\" ");
         }
         if (propertySetId != null) {
-            writer.write("PropertySetId=\"");
-            writer.write(propertySetId);
-            writer.write("\" ");
+            buffer.append("PropertySetId=\"").append(propertySetId).append("\" ");
         }
         if (propertyId != 0) {
-            writer.write("PropertyId=\"");
-            writer.write(String.valueOf(propertyId));
-            writer.write("\" ");
+            buffer.append("PropertyId=\"").append(String.valueOf(propertyId)).append("\" ");
         }
-        writer.write("PropertyType=\"");
-        writer.write(propertyType.toString());
-        writer.write("\"/>");
+        buffer.append("PropertyType=\"").append(propertyType.toString()).append("\"/>");
     }
 
     public static final ExtendedFieldURI PR_INSTANCE_KEY = new ExtendedFieldURI("0x0FF6", PropertyType.Binary);
@@ -80,7 +72,8 @@ public class ExtendedFieldURI implements FieldURI {
     public static final ExtendedFieldURI PR_FLAG_STATUS = new ExtendedFieldURI("0x1090", PropertyType.Integer);
     public static final ExtendedFieldURI PR_MESSAGE_FLAGS = new ExtendedFieldURI("0x0E07", PropertyType.Integer);
     public static final ExtendedFieldURI PR_ACTION_FLAG = new ExtendedFieldURI("0x1081", PropertyType.Integer);
-    public static final ExtendedFieldURI PR_URL_COMP_NAME = new ExtendedFieldURI("0x10F3", PropertyType.String);
+    public static final ExtendedFieldURI PR_URL_COMP_NAME = new ExtendedFieldURI("0x10f3", PropertyType.String);
+    public static final ExtendedFieldURI PR_CONTAINER_CLASS = new ExtendedFieldURI("0x3613", PropertyType.String);
 
     public static final ExtendedFieldURI PR_LAST_MODIFICATION_TIME = new ExtendedFieldURI("0x3008", PropertyType.SystemTime);
 
diff --git a/src/java/davmail/exchange/ews/FieldURI.java b/src/java/davmail/exchange/ews/FieldURI.java
index b5b39147..48326a30 100644
--- a/src/java/davmail/exchange/ews/FieldURI.java
+++ b/src/java/davmail/exchange/ews/FieldURI.java
@@ -26,6 +26,6 @@ import java.io.Writer;
  */
 public interface FieldURI {
 
-    public void write(Writer writer) throws IOException;
+    public void appendTo(StringBuilder buffer);
 
 }
diff --git a/src/java/davmail/exchange/ews/MultipleOperandBooleanExpression.java b/src/java/davmail/exchange/ews/MultipleOperandBooleanExpression.java
index 6a0455cb..3971e5b0 100644
--- a/src/java/davmail/exchange/ews/MultipleOperandBooleanExpression.java
+++ b/src/java/davmail/exchange/ews/MultipleOperandBooleanExpression.java
@@ -37,17 +37,13 @@ public class MultipleOperandBooleanExpression implements SearchExpression {
         this.operator = operator;
     }
 
-    public void write(Writer writer) throws IOException {
-        writer.write("<t:");
-        writer.write(operator.toString());
-        writer.write(">");
+    public void appendTo(StringBuilder buffer) {
+        buffer.append("<t:").append(operator.toString()).append('>');
 
         for (SearchExpression searchExpression : searchExpressions) {
-            searchExpression.write(writer);
+            searchExpression.appendTo(buffer);
         }
 
-        writer.write("</t:");
-        writer.write(operator.toString());
-        writer.write(">");
+        buffer.append("</t:").append(operator.toString()).append('>');
     }
 }
diff --git a/src/java/davmail/exchange/ews/SearchExpression.java b/src/java/davmail/exchange/ews/SearchExpression.java
index 4dd8a260..d5b61430 100644
--- a/src/java/davmail/exchange/ews/SearchExpression.java
+++ b/src/java/davmail/exchange/ews/SearchExpression.java
@@ -25,11 +25,5 @@ import java.io.Writer;
  * EWS Search Expression.
  */
 public interface SearchExpression {
-    /**
-     * Write XML content to writer.
-     *
-     * @param writer writer
-     * @throws IOException on error
-     */
-    public void write(Writer writer) throws IOException;
+     public void appendTo(StringBuilder buffer);
 }
diff --git a/src/java/davmail/exchange/ews/TwoOperandExpression.java b/src/java/davmail/exchange/ews/TwoOperandExpression.java
index 6e346a78..1146f69e 100644
--- a/src/java/davmail/exchange/ews/TwoOperandExpression.java
+++ b/src/java/davmail/exchange/ews/TwoOperandExpression.java
@@ -18,6 +18,8 @@
  */
 package davmail.exchange.ews;
 
+import davmail.util.StringUtil;
+
 import java.io.IOException;
 import java.io.Writer;
 
@@ -46,19 +48,15 @@ public class TwoOperandExpression implements SearchExpression {
         this.value = value;
     }
 
-    public void write(Writer writer) throws IOException {
-        writer.write("<t:");
-        writer.write(operator.toString());
-        writer.write(">");
-        fieldURI.write(writer);
+    public void appendTo(StringBuilder buffer) {
+        buffer.append("<t:").append(operator.toString()).append('>');
+        fieldURI.appendTo(buffer);
 
-        writer.write("<t:FieldURIOrConstant><t:Constant Value=\"");
-        writer.write(value);
-        writer.write("\"/></t:FieldURIOrConstant>");
+        buffer.append("<t:FieldURIOrConstant><t:Constant Value=\"");
+        buffer.append(StringUtil.xmlEncode(value));
+        buffer.append("\"/></t:FieldURIOrConstant>");
 
-        writer.write("</t:");
-        writer.write(operator.toString());
-        writer.write(">");
+        buffer.append("</t:").append(operator.toString()).append('>');
     }
 
 }
diff --git a/src/java/davmail/exchange/ews/UnindexedFieldURI.java b/src/java/davmail/exchange/ews/UnindexedFieldURI.java
index e5d99a03..d7ef602d 100644
--- a/src/java/davmail/exchange/ews/UnindexedFieldURI.java
+++ b/src/java/davmail/exchange/ews/UnindexedFieldURI.java
@@ -31,12 +31,10 @@ public class UnindexedFieldURI implements FieldURI {
         this.fieldURI = fieldURI;
     }
 
-    public void write(Writer writer) throws IOException {
-        writer.write("<t:FieldURI FieldURI=\"");
-        writer.write(fieldURI);
-        writer.write("\"/>");
+    public void appendTo(StringBuilder buffer) {
+        buffer.append("<t:FieldURI FieldURI=\"").append(fieldURI).append("\"/>");
     }
 
     public static final UnindexedFieldURI DATE_TIME_SENT = new UnindexedFieldURI("item:DateTimeSent");
-    
+
 }
diff --git a/src/java/davmailmessages.properties b/src/java/davmailmessages.properties
index cec740a8..50df8346 100644
--- a/src/java/davmailmessages.properties
+++ b/src/java/davmailmessages.properties
@@ -257,3 +257,4 @@ UI_IMAP_AUTO_EXPUNGE=IMAP auto expunge:
 UI_IMAP_AUTO_EXPUNGE_HELP=Delete messages immediately on the server over IMAP
 UI_IMAP_IDLE_DELAY=IDLE folder monitor delay (IMAP):
 UI_IMAP_IDLE_DELAY_HELP=IMAP folder idle monitor delay in minutes, leave empty to disable IDLE support
+EXCEPTION_EWS_NOT_AVAILABLE=EWS end point not available
diff --git a/src/java/davmailmessages_fr.properties b/src/java/davmailmessages_fr.properties
index a79417df..267d02a8 100644
--- a/src/java/davmailmessages_fr.properties
+++ b/src/java/davmailmessages_fr.properties
@@ -255,4 +255,5 @@ LOG_READ_CLIENT_AUTH_LOGIN=< AUTH LOGIN ********
 UI_IMAP_IDLE_DELAY=Délai de surveillance dossier (IMAP) :
 UI_IMAP_IDLE_DELAY_HELP=Délai de surveillance du dossier IMAP en minutes, laisser vide pour désactiver le support IDLE
 UI_IMAP_AUTO_EXPUNGE=IMAP suppression immédiate :
-UI_IMAP_AUTO_EXPUNGE_HELP=Supprimer immédiatement les messages du serveur via IMAP
\ No newline at end of file
+UI_IMAP_AUTO_EXPUNGE_HELP=Supprimer immédiatement les messages du serveur via IMAP
+EXCEPTION_EWS_NOT_AVAILABLE=Point d''accès EWS non disponible