diff --git a/src/java/davmail/exchange/ExchangeSessionFactory.java b/src/java/davmail/exchange/ExchangeSessionFactory.java
index eca061ad..aece22f2 100644
--- a/src/java/davmail/exchange/ExchangeSessionFactory.java
+++ b/src/java/davmail/exchange/ExchangeSessionFactory.java
@@ -118,6 +118,11 @@ public final class ExchangeSessionFactory {
         return session;
     }
 
+    /**
+     * Send a request to Exchange server to check current settings.
+     * 
+     * @throws IOException if unable to access Exchange server
+     */
     public static void checkConfig() throws IOException {
         String url = Settings.getProperty("davmail.url");
         HttpClient httpClient = DavGatewayHttpClientFacade.getInstance();
@@ -187,6 +192,9 @@ public final class ExchangeSessionFactory {
         return up;
     }
 
+    /**
+     * Reset config check status and clear session pool.
+     */
     public static void reset() {
         configChecked = false;
         poolMap.clear();
diff --git a/src/java/davmail/exchange/ICSBufferedReader.java b/src/java/davmail/exchange/ICSBufferedReader.java
index 6eb182f8..cf37ce94 100644
--- a/src/java/davmail/exchange/ICSBufferedReader.java
+++ b/src/java/davmail/exchange/ICSBufferedReader.java
@@ -30,11 +30,19 @@ public class ICSBufferedReader extends BufferedReader {
     protected String nextLine;
     protected final StringBuilder currentLine = new StringBuilder(75);
 
+    /**
+     * Create an ICS reader on the provided reader
+     * @param in input reader
+     * @throws IOException on error
+     */
     public ICSBufferedReader(Reader in) throws IOException {
         super(in);
         nextLine = super.readLine();
     }
 
+    /**
+     * Read a line from input reader, unwrap long lines.
+     */
     @Override
     public String readLine() throws IOException {
         if (nextLine == null) {
diff --git a/src/java/davmail/exchange/ICSBufferedWriter.java b/src/java/davmail/exchange/ICSBufferedWriter.java
index 6af0312e..b5824c87 100644
--- a/src/java/davmail/exchange/ICSBufferedWriter.java
+++ b/src/java/davmail/exchange/ICSBufferedWriter.java
@@ -25,6 +25,10 @@ package davmail.exchange;
 public class ICSBufferedWriter {
     final StringBuilder buffer = new StringBuilder();
 
+    /**
+     * Write line to buffer, split lines at 75 characters.
+     * @param line ics event line
+     */
     public void writeLine(String line) {
         if (line.length() > 75) {
             buffer.append(line.substring(0, 75));
@@ -37,10 +41,14 @@ public class ICSBufferedWriter {
         }
     }
 
-    public void newLine() {
+    protected void newLine() {
         buffer.append((char) 13).append((char) 10);
     }
 
+    /**
+     * Get buffer as String
+     * @return ICS content as String
+     */
     @Override
     public String toString() {
       return buffer.toString();  
diff --git a/src/java/davmail/exchange/NetworkDownException.java b/src/java/davmail/exchange/NetworkDownException.java
index 0a177887..b92d390f 100644
--- a/src/java/davmail/exchange/NetworkDownException.java
+++ b/src/java/davmail/exchange/NetworkDownException.java
@@ -24,6 +24,10 @@ import davmail.exception.DavMailException;
  * Custom exception to mark network down case.
  */
 public class NetworkDownException extends DavMailException {
+    /**
+     * Build a network down exception with the provided BundleMessage key.
+     * @param key message key
+     */
     public NetworkDownException(String key) {
         super(key);
     }