diff --git a/src/java/davmail/caldav/CaldavConnection.java b/src/java/davmail/caldav/CaldavConnection.java
index 63e1dd1c..c2c21bf2 100644
--- a/src/java/davmail/caldav/CaldavConnection.java
+++ b/src/java/davmail/caldav/CaldavConnection.java
@@ -731,7 +731,7 @@ public class CaldavConnection extends AbstractConnection {
 
     }
 
-    protected class CaldavRequest {
+    protected static class CaldavRequest {
         protected HashSet<String> properties = new HashSet<String>();
         protected HashSet<String> hrefs;
         protected boolean isMultiGet;
diff --git a/src/java/davmail/exchange/ICSBufferedReader.java b/src/java/davmail/exchange/ICSBufferedReader.java
index a0085d3b..0f0859ea 100644
--- a/src/java/davmail/exchange/ICSBufferedReader.java
+++ b/src/java/davmail/exchange/ICSBufferedReader.java
@@ -10,6 +10,7 @@ import java.io.IOException;
  */
 public class ICSBufferedReader extends BufferedReader {
     protected String nextLine;
+    protected StringBuilder currentLine = new StringBuilder(75);
 
     public ICSBufferedReader(Reader in, int sz) throws IOException {
         super(in, sz);
@@ -23,12 +24,17 @@ public class ICSBufferedReader extends BufferedReader {
 
     @Override
     public String readLine() throws IOException {
-        String currentLine = nextLine;
-        nextLine = super.readLine();
-        while (nextLine != null && nextLine.charAt(0) == ' ') {
-            currentLine += nextLine.substring(1);
+        if (nextLine == null) {
+            return null;
+        } else {
+            currentLine.setLength(0);
+            currentLine.append(nextLine);
             nextLine = super.readLine();
+            while (nextLine != null && nextLine.charAt(0) == ' ') {
+                currentLine.append(nextLine.substring(1));
+                nextLine = super.readLine();
+            }
+            return currentLine.toString();
         }
-        return currentLine;
     }
 }
diff --git a/src/java/davmail/imap/ImapConnection.java b/src/java/davmail/imap/ImapConnection.java
index fef028c7..da850bca 100644
--- a/src/java/davmail/imap/ImapConnection.java
+++ b/src/java/davmail/imap/ImapConnection.java
@@ -135,7 +135,9 @@ public class ImapConnection extends AbstractConnection {
     }
 
     /**
-     * Decode SMTP credentials
+     * Decode IMAP credentials
+     * @param tokens tokens
+     * @throws java.io.IOException on error
      */
     protected void parseCredentials(StringTokenizer tokens) throws IOException {
         if (tokens.hasMoreTokens()) {
diff --git a/src/java/davmail/imap/ImapServer.java b/src/java/davmail/imap/ImapServer.java
index 9515bb51..e53e82c0 100644
--- a/src/java/davmail/imap/ImapServer.java
+++ b/src/java/davmail/imap/ImapServer.java
@@ -16,6 +16,9 @@ public class ImapServer extends AbstractServer {
     /**
      * Create a ServerSocket to listen for connections.
      * Start the thread.
+     *
+     * @param port imap listen port, 143 if not defined (0)
+     * @throws java.io.IOException on error
      */
     public ImapServer(int port) throws IOException {
         super("ImapServer", port, ImapServer.DEFAULT_PORT);