diff --git a/greenmail-core/pom.xml b/greenmail-core/pom.xml
index e9d8e2ab82..cff7efa2cc 100644
--- a/greenmail-core/pom.xml
+++ b/greenmail-core/pom.xml
@@ -61,6 +61,21 @@
       <groupId>org.hamcrest</groupId>
       <artifactId>hamcrest-all</artifactId>
     </dependency>
+    <dependency>
+      <groupId>org.easymock</groupId>
+      <artifactId>easymock</artifactId>
+      <scope>test</scope>
+    </dependency>
+    <dependency>
+      <groupId>org.powermock</groupId>
+      <artifactId>powermock-module-junit4</artifactId>
+      <scope>test</scope>
+    </dependency>
+    <dependency>
+      <groupId>org.powermock</groupId>
+      <artifactId>powermock-api-easymock</artifactId>
+      <scope>test</scope>
+    </dependency>
   </dependencies>
 
 </project>
diff --git a/greenmail-core/src/main/java/com/icegreen/greenmail/Managers.java b/greenmail-core/src/main/java/com/icegreen/greenmail/Managers.java
index c70f1470a1..47ee069037 100644
--- a/greenmail-core/src/main/java/com/icegreen/greenmail/Managers.java
+++ b/greenmail-core/src/main/java/com/icegreen/greenmail/Managers.java
@@ -8,6 +8,7 @@
 import com.icegreen.greenmail.imap.ImapHostManagerImpl;
 import com.icegreen.greenmail.smtp.SmtpManager;
 import com.icegreen.greenmail.store.InMemoryStore;
+import com.icegreen.greenmail.store.Store;
 import com.icegreen.greenmail.user.UserManager;
 
 /**
@@ -16,19 +17,39 @@
  * @since Jan 27, 2006
  */
 public class Managers {
-    private ImapHostManager imapHostManager = new ImapHostManagerImpl(new InMemoryStore());
-    private UserManager userManager = new UserManager(imapHostManager);
-    private SmtpManager smtpManager = new SmtpManager(imapHostManager, userManager);
+    private ImapHostManager imapHostManager;
+    private UserManager userManager;
+    private SmtpManager smtpManager;
 
-    public SmtpManager getSmtpManager() {
+    public Managers() {
+        this(new InMemoryStore());
+    }
+
+    protected Managers(final Store imapHostManagerStore) {
+        imapHostManager = new ImapHostManagerImpl(imapHostManagerStore);
+        userManager = new UserManager(imapHostManager);
+        smtpManager = new SmtpManager(imapHostManager, userManager);
+    }
+
+    public final SmtpManager getSmtpManager() {
         return smtpManager;
     }
 
-    public UserManager getUserManager() {
+    public final UserManager getUserManager() {
         return userManager;
     }
 
-    public ImapHostManager getImapHostManager() {
+    public final ImapHostManager getImapHostManager() {
         return imapHostManager;
     }
+
+    public final void reset() {
+        imapHostManager = new ImapHostManagerImpl(createNewStore());
+        userManager = new UserManager(imapHostManager);
+        smtpManager = new SmtpManager(imapHostManager, userManager);
+    }
+
+    protected Store createNewStore() {
+        return new InMemoryStore();
+    }
 }
diff --git a/greenmail-core/src/main/java/com/icegreen/greenmail/MemorySafeManagers.java b/greenmail-core/src/main/java/com/icegreen/greenmail/MemorySafeManagers.java
new file mode 100644
index 0000000000..2f31616ac9
--- /dev/null
+++ b/greenmail-core/src/main/java/com/icegreen/greenmail/MemorySafeManagers.java
@@ -0,0 +1,29 @@
+/*
+ *  -------------------------------------------------------------------
+ *  This software is released under the Apache license 2.0
+ *  -------------------------------------------------------------------
+ * /
+ */
+
+package com.icegreen.greenmail;
+
+import com.icegreen.greenmail.store.InMemoryStore;
+import com.icegreen.greenmail.store.Store;
+import com.icegreen.greenmail.store.StoredMessageCollectionFactory;
+
+/**
+ * {@link Managers} which uses the {@link StoredMessageCollectionFactory#MAP_BASED_FACTORY MAP_BASED_FACTORY} for
+ * instantiating the {@link InMemoryStore}.
+ *
+ * @author Raimund Klein <raimund.klein@gmx.de>
+ */
+public class MemorySafeManagers extends Managers {
+    public MemorySafeManagers() {
+        super(new InMemoryStore(StoredMessageCollectionFactory.MAP_BASED_FACTORY));
+    }
+
+    @Override
+    protected Store createNewStore() {
+        return new InMemoryStore(StoredMessageCollectionFactory.MAP_BASED_FACTORY);
+    }
+}
diff --git a/greenmail-core/src/main/java/com/icegreen/greenmail/configuration/ConfiguredGreenMail.java b/greenmail-core/src/main/java/com/icegreen/greenmail/configuration/ConfiguredGreenMail.java
index b01b64dee1..5020fa79ca 100644
--- a/greenmail-core/src/main/java/com/icegreen/greenmail/configuration/ConfiguredGreenMail.java
+++ b/greenmail-core/src/main/java/com/icegreen/greenmail/configuration/ConfiguredGreenMail.java
@@ -1,13 +1,36 @@
 package com.icegreen.greenmail.configuration;
 
+import com.icegreen.greenmail.Managers;
 import com.icegreen.greenmail.base.GreenMailOperations;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
 
 /**
  * A version of GreenMailOperations that implements the configure() method.
  */
 public abstract class ConfiguredGreenMail implements GreenMailOperations {
+    protected final Logger log = LoggerFactory.getLogger(getClass());
     private GreenMailConfiguration config;
 
+    protected final Managers createManagers() {
+        if (config == null)
+            config = GreenMailConfiguration.aConfig();
+        Class<? extends Managers> configuredManagersClass = config.getManagersClass();
+        try {
+            return configuredManagersClass.newInstance();
+        } catch (InstantiationException e) {
+            log.warn(String.format("Could not instantiate Managers class '%s'. Will run with default class '%s'.",
+                    configuredManagersClass, Managers.class), e);
+        } catch (IllegalAccessException e) {
+            log.warn(String.format("Illegal access while instantiating Managers class '%s'. Will run with default " +
+                    "class '%s'.", configuredManagersClass, Managers.class), e);
+        } catch (Exception e) {
+            log.warn(String.format("General exception while instantiating Managers class '%s'. Will run with default " +
+                    "class '%s'.", configuredManagersClass, Managers.class), e);
+        }
+        return new Managers();
+    }
+
     @Override
     public ConfiguredGreenMail withConfiguration(GreenMailConfiguration config) {
         this.config = config;
diff --git a/greenmail-core/src/main/java/com/icegreen/greenmail/configuration/GreenMailConfiguration.java b/greenmail-core/src/main/java/com/icegreen/greenmail/configuration/GreenMailConfiguration.java
index ad6fbf1519..9381dfabfd 100644
--- a/greenmail-core/src/main/java/com/icegreen/greenmail/configuration/GreenMailConfiguration.java
+++ b/greenmail-core/src/main/java/com/icegreen/greenmail/configuration/GreenMailConfiguration.java
@@ -1,5 +1,7 @@
 package com.icegreen.greenmail.configuration;
 
+import com.icegreen.greenmail.Managers;
+
 import java.util.ArrayList;
 import java.util.List;
 
@@ -8,6 +10,14 @@
  */
 public class GreenMailConfiguration {
     private final List<UserBean> usersToCreate = new ArrayList<UserBean>();
+    private Class<? extends Managers> managersClass = Managers.class;
+
+    /**
+     * @return New GreenMail configuration
+     */
+    public static GreenMailConfiguration aConfig() {
+        return new GreenMailConfiguration();
+    }
 
     /**
      * The given {@link com.icegreen.greenmail.user.GreenMailUser} will be created when servers will start
@@ -33,11 +43,12 @@ public GreenMailConfiguration withUser(final String email, final String login, f
         return this;
     }
 
-    /**
-     * @return New GreenMail configuration
-     */
-    public static GreenMailConfiguration aConfig() {
-        return new GreenMailConfiguration();
+    public GreenMailConfiguration withManagersClass(final Class<? extends Managers> managersClass) {
+        if (managersClass == null) {
+            throw new NullPointerException("managersClass may not be null.");
+        }
+        this.managersClass = managersClass;
+        return this;
     }
 
     /**
@@ -46,4 +57,11 @@ public static GreenMailConfiguration aConfig() {
     public List<UserBean> getUsersToCreate() {
         return usersToCreate;
     }
+
+    /**
+     * @return The {@link Managers} class to should be used
+     */
+    public Class<? extends Managers> getManagersClass() {
+        return managersClass;
+    }
 }
diff --git a/greenmail-core/src/main/java/com/icegreen/greenmail/imap/ImapHostManagerImpl.java b/greenmail-core/src/main/java/com/icegreen/greenmail/imap/ImapHostManagerImpl.java
index 172ce3bc09..5c82fc722d 100644
--- a/greenmail-core/src/main/java/com/icegreen/greenmail/imap/ImapHostManagerImpl.java
+++ b/greenmail-core/src/main/java/com/icegreen/greenmail/imap/ImapHostManagerImpl.java
@@ -28,8 +28,7 @@ public class ImapHostManagerImpl
      * Hack constructor which creates an in-memory store, and creates a console logger.
      */
     public ImapHostManagerImpl() {
-        store = new InMemoryStore();
-        subscriptions = new MailboxSubscriptions();
+        this(new InMemoryStore());
     }
 
     public ImapHostManagerImpl(Store store) {
@@ -294,6 +293,10 @@ private String getQualifiedMailboxName(GreenMailUser user, String mailboxName) {
         }
     }
 
+    public Store getStore() {
+        return store;
+    }
+
     /**
      * Handles all user subscriptions.
      * TODO make this a proper class
@@ -348,9 +351,4 @@ private List<String> getUserSubs(GreenMailUser user) {
             return subs;
         }
     }
-
-    @Override
-    public Store getStore() {
-        return store;
-    }
 }
diff --git a/greenmail-core/src/main/java/com/icegreen/greenmail/mail/MovingMessage.java b/greenmail-core/src/main/java/com/icegreen/greenmail/mail/MovingMessage.java
index fbbfd15d04..cc1e748b02 100644
--- a/greenmail-core/src/main/java/com/icegreen/greenmail/mail/MovingMessage.java
+++ b/greenmail-core/src/main/java/com/icegreen/greenmail/mail/MovingMessage.java
@@ -37,14 +37,14 @@ public class MovingMessage {
     private MimeMessage message;
     private int _references = 0;
 
-    public List<MailAddress> getToAddresses() {
-        return toAddresses;
-    }
-
     public MovingMessage(Workspace workspace) {
         _workspace = workspace;
     }
 
+    public List<MailAddress> getToAddresses() {
+        return toAddresses;
+    }
+
     public MimeMessage getMessage() {
         return message;
     }
diff --git a/greenmail-core/src/main/java/com/icegreen/greenmail/server/AbstractServer.java b/greenmail-core/src/main/java/com/icegreen/greenmail/server/AbstractServer.java
index 815cfc75e5..f3076b3682 100644
--- a/greenmail-core/src/main/java/com/icegreen/greenmail/server/AbstractServer.java
+++ b/greenmail-core/src/main/java/com/icegreen/greenmail/server/AbstractServer.java
@@ -26,13 +26,13 @@
 public abstract class AbstractServer extends Thread implements Service {
     protected final Logger log = LoggerFactory.getLogger(getClass());
     protected final InetAddress bindTo;
+    private final List<ProtocolHandler> handlers = Collections.synchronizedList(new ArrayList<ProtocolHandler>());
+    private final Object startupMonitor = new Object();
     protected ServerSocket serverSocket = null;
     protected Managers managers;
     protected ServerSetup setup;
-    private final List<ProtocolHandler> handlers = Collections.synchronizedList(new ArrayList<ProtocolHandler>());
     private volatile boolean keepRunning = false;
     private volatile boolean running = false;
-    private final Object startupMonitor = new Object();
 
     protected AbstractServer(ServerSetup setup, Managers managers) {
         this.setup = setup;
diff --git a/greenmail-core/src/main/java/com/icegreen/greenmail/store/HierarchicalFolder.java b/greenmail-core/src/main/java/com/icegreen/greenmail/store/HierarchicalFolder.java
index 8dbc2bdb7f..f5006bdc82 100644
--- a/greenmail-core/src/main/java/com/icegreen/greenmail/store/HierarchicalFolder.java
+++ b/greenmail-core/src/main/java/com/icegreen/greenmail/store/HierarchicalFolder.java
@@ -30,7 +30,8 @@ class HierarchicalFolder implements MailFolder, UIDFolder {
         PERMANENT_FLAGS.add(Flags.Flag.SEEN);
     }
 
-    private final StoredMessageCollection mailMessages = new ListBasedStoredMessageCollection();
+    private final StoredMessageCollectionFactory storedMessageCollectionFactory;
+    private final StoredMessageCollection mailMessages;
     private final List<FolderListener> _mailboxListeners = Collections.synchronizedList(new ArrayList<FolderListener>());
     protected String name;
     private Collection<HierarchicalFolder> children;
@@ -39,14 +40,20 @@ class HierarchicalFolder implements MailFolder, UIDFolder {
     private long nextUid = 1;
     private long uidValidity;
 
-    public HierarchicalFolder(HierarchicalFolder parent,
-                              String name) {
+    protected HierarchicalFolder(final StoredMessageCollectionFactory storedMessageCollectionFactory,
+                                 HierarchicalFolder parent, String name) {
+        this.storedMessageCollectionFactory = storedMessageCollectionFactory;
+        mailMessages = storedMessageCollectionFactory.createCollection();
         this.name = name;
         this.children = new ArrayList<HierarchicalFolder>();
         this.parent = parent;
         this.uidValidity = System.currentTimeMillis();
     }
 
+    public HierarchicalFolder(final HierarchicalFolder castParent, final String mailboxName) {
+        this(castParent.storedMessageCollectionFactory, castParent, mailboxName);
+    }
+
     public Collection<HierarchicalFolder> getChildren() {
         return children;
     }
diff --git a/greenmail-core/src/main/java/com/icegreen/greenmail/store/InMemoryStore.java b/greenmail-core/src/main/java/com/icegreen/greenmail/store/InMemoryStore.java
index 5630f710a2..5b6bd0e4e9 100644
--- a/greenmail-core/src/main/java/com/icegreen/greenmail/store/InMemoryStore.java
+++ b/greenmail-core/src/main/java/com/icegreen/greenmail/store/InMemoryStore.java
@@ -21,10 +21,18 @@
  */
 public class InMemoryStore
         implements Store, ImapConstants {
+    private final RootFolder rootMailbox;
     boolean quotaSupported = true;
-    private RootFolder rootMailbox = new RootFolder();
     private Map<String, Set<Quota>> quotaMap = new HashMap<String, Set<Quota>>();
 
+    public InMemoryStore() {
+        this(StoredMessageCollectionFactory.LIST_BASED_FACTORY);
+    }
+
+    public InMemoryStore(final StoredMessageCollectionFactory storedMessageCollectionFactory) {
+        this.rootMailbox = new RootFolder(storedMessageCollectionFactory);
+    }
+
     @Override
     public MailFolder getMailbox(String absoluteMailboxName) {
         StringTokenizer tokens = new StringTokenizer(absoluteMailboxName, HIERARCHY_DELIMITER);
diff --git a/greenmail-core/src/main/java/com/icegreen/greenmail/store/RootFolder.java b/greenmail-core/src/main/java/com/icegreen/greenmail/store/RootFolder.java
index 58360a4700..bc0af12701 100644
--- a/greenmail-core/src/main/java/com/icegreen/greenmail/store/RootFolder.java
+++ b/greenmail-core/src/main/java/com/icegreen/greenmail/store/RootFolder.java
@@ -10,8 +10,8 @@
  * @author Raimund Klein <raimund.klein@gmx.de>
  */
 class RootFolder extends HierarchicalFolder {
-    public RootFolder() {
-        super(null, ImapConstants.USER_NAMESPACE);
+    RootFolder(final StoredMessageCollectionFactory storedMessageCollectionFactory) {
+        super(storedMessageCollectionFactory, null, ImapConstants.USER_NAMESPACE);
     }
 
     @Override
diff --git a/greenmail-core/src/main/java/com/icegreen/greenmail/store/StoredMessageCollectionFactory.java b/greenmail-core/src/main/java/com/icegreen/greenmail/store/StoredMessageCollectionFactory.java
new file mode 100644
index 0000000000..209681d5f8
--- /dev/null
+++ b/greenmail-core/src/main/java/com/icegreen/greenmail/store/StoredMessageCollectionFactory.java
@@ -0,0 +1,75 @@
+/* -------------------------------------------------------------------
+* This software is released under the Apache license 2.0
+* -------------------------------------------------------------------
+*/
+package com.icegreen.greenmail.store;
+
+import java.util.HashSet;
+import java.util.Map;
+import java.util.Set;
+import java.util.concurrent.ConcurrentHashMap;
+
+/**
+ * @author Raimund Klein <raimund.klein@gmx.de>
+ */
+public enum StoredMessageCollectionFactory {
+    LIST_BASED_FACTORY {
+        @Override
+        StoredMessageCollection createCollection() {
+            return new ListBasedStoredMessageCollection();
+        }
+    },
+    MAP_BASED_FACTORY {
+        private static final int DEFAULT_MAXIMUM_MAP_SIZE = 5000;
+
+        @Override
+        protected Set<String> getAcceptedConfigurationKeys() {
+            final Set acceptedKeys = super.getAcceptedConfigurationKeys();
+            acceptedKeys.add(Constants.CONFIGURATION_KEY_MAXIMUM_MAP_SIZE);
+            return acceptedKeys;
+        }
+
+        @Override
+        StoredMessageCollection createCollection() {
+            final int maximumMapSize = hasConfigurationFor(Constants.CONFIGURATION_KEY_MAXIMUM_MAP_SIZE) ?
+                    (Integer) getConfiguredValue
+                            (Constants.CONFIGURATION_KEY_MAXIMUM_MAP_SIZE) : DEFAULT_MAXIMUM_MAP_SIZE;
+            return new MapBasedStoredMessageCollection(maximumMapSize);
+        }
+    };
+
+    private final Map<String, Object> configuration;
+
+    StoredMessageCollectionFactory() {
+        configuration = new ConcurrentHashMap<String, Object>();
+    }
+
+    abstract StoredMessageCollection createCollection();
+
+    protected Set<String> getAcceptedConfigurationKeys() {
+        return new HashSet<String>();
+    }
+
+    protected final Object getConfiguredValue(final String configurationKey) {
+        return configuration.get(configurationKey);
+    }
+
+    protected final boolean hasConfigurationFor(final String configurationKey) {
+        return configuration.containsKey(configurationKey);
+    }
+
+    public final StoredMessageCollectionFactory withConfigurationValue(final String key, final Object value) {
+        final Set<String> acceptedKeys = getAcceptedConfigurationKeys();
+        if (acceptedKeys.contains(key)) {
+            configuration.put(key, value);
+            return this;
+        }
+
+        throw new IllegalArgumentException(String.format("Configuration key '%s' unknown. Accepted keys are:%s", key,
+                acceptedKeys));
+    }
+
+    public static class Constants {
+        public static final String CONFIGURATION_KEY_MAXIMUM_MAP_SIZE = "CONFIGURATION_KEY_MAXIMUM_MAP_SIZE";
+    }
+}
diff --git a/greenmail-core/src/main/java/com/icegreen/greenmail/user/UserImpl.java b/greenmail-core/src/main/java/com/icegreen/greenmail/user/UserImpl.java
index ec2d66602e..8c309baf9d 100644
--- a/greenmail-core/src/main/java/com/icegreen/greenmail/user/UserImpl.java
+++ b/greenmail-core/src/main/java/com/icegreen/greenmail/user/UserImpl.java
@@ -16,9 +16,9 @@
 
 
 public class UserImpl implements GreenMailUser {
-    String email;
     private final int cachedHashCode;
     private final String cachedHashCodeAsString;
+    String email;
     String login;
     String password;
     private ImapHostManager imapHostManager;
@@ -46,9 +46,9 @@ public void delete() {
         try {
             imapHostManager.deleteMailbox(this, ImapConstants.INBOX_NAME);
         } catch (FolderException e) {
-            throw new IllegalStateException("Can not delete user "+this, e);
+            throw new IllegalStateException("Can not delete user " + this, e);
         } catch (AuthorizationException e) {
-            throw new IllegalStateException("Can not delete user "+this, e);
+            throw new IllegalStateException("Can not delete user " + this, e);
         }
     }
 
diff --git a/greenmail-core/src/main/java/com/icegreen/greenmail/util/GreenMail.java b/greenmail-core/src/main/java/com/icegreen/greenmail/util/GreenMail.java
index 1c5354f2c9..c901dc9980 100644
--- a/greenmail-core/src/main/java/com/icegreen/greenmail/util/GreenMail.java
+++ b/greenmail-core/src/main/java/com/icegreen/greenmail/util/GreenMail.java
@@ -58,12 +58,36 @@ public GreenMail(ServerSetup[] config) {
         init();
     }
 
+    /**
+     * Create the required services according to the server setup
+     *
+     * @param config Service configuration
+     * @return Services map
+     */
+    private static Map<String, AbstractServer> createServices(ServerSetup[] config, Managers mgr) {
+        Map<String, AbstractServer> srvc = new HashMap<String, AbstractServer>();
+        for (ServerSetup setup : config) {
+            if (srvc.containsKey(setup.getProtocol())) {
+                throw new IllegalArgumentException("Server '" + setup.getProtocol() + "' was found at least twice in the array");
+            }
+            final String protocol = setup.getProtocol();
+            if (protocol.startsWith(ServerSetup.PROTOCOL_SMTP)) {
+                srvc.put(protocol, new SmtpServer(setup, mgr));
+            } else if (protocol.startsWith(ServerSetup.PROTOCOL_POP3)) {
+                srvc.put(protocol, new Pop3Server(setup, mgr));
+            } else if (protocol.startsWith(ServerSetup.PROTOCOL_IMAP)) {
+                srvc.put(protocol, new ImapServer(setup, mgr));
+            }
+        }
+        return srvc;
+    }
+
     /**
      * Initialize
      */
     private void init() {
         if (managers == null) {
-            managers = new Managers();
+            managers = createManagers();
         }
         if(services == null) {
             services = createServices(config, managers);
@@ -118,7 +142,7 @@ public synchronized void stop() {
                 service.stopService();
             }
         }
-        managers = new Managers();
+        managers.reset();
         services = null;
     }
 
@@ -128,30 +152,6 @@ public void reset() {
         start();
     }
 
-    /**
-     * Create the required services according to the server setup
-     *
-     * @param config Service configuration
-     * @return Services map
-     */
-    private static Map<String, AbstractServer> createServices(ServerSetup[] config, Managers mgr) {
-        Map<String, AbstractServer> srvc = new HashMap<String, AbstractServer>();
-        for (ServerSetup setup : config) {
-            if (srvc.containsKey(setup.getProtocol())) {
-                throw new IllegalArgumentException("Server '" + setup.getProtocol() + "' was found at least twice in the array");
-            }
-            final String protocol = setup.getProtocol();
-            if (protocol.startsWith(ServerSetup.PROTOCOL_SMTP)) {
-                srvc.put(protocol, new SmtpServer(setup, mgr));
-            } else if (protocol.startsWith(ServerSetup.PROTOCOL_POP3)) {
-                srvc.put(protocol, new Pop3Server(setup, mgr));
-            } else if (protocol.startsWith(ServerSetup.PROTOCOL_IMAP)) {
-                srvc.put(protocol, new ImapServer(setup, mgr));
-            }
-        }
-        return srvc;
-    }
-
     @Override
     public SmtpServer getSmtp() {
         return (SmtpServer) services.get(ServerSetup.PROTOCOL_SMTP);
diff --git a/greenmail-core/src/test/java/com/icegreen/greenmail/ManagersTest.java b/greenmail-core/src/test/java/com/icegreen/greenmail/ManagersTest.java
new file mode 100644
index 0000000000..32864ce59b
--- /dev/null
+++ b/greenmail-core/src/test/java/com/icegreen/greenmail/ManagersTest.java
@@ -0,0 +1,126 @@
+/*
+ *  -------------------------------------------------------------------
+ *  This software is released under the Apache license 2.0
+ *  -------------------------------------------------------------------
+ * /
+ */
+
+package com.icegreen.greenmail;
+
+import com.icegreen.greenmail.imap.ImapHostManagerImpl;
+import com.icegreen.greenmail.smtp.SmtpManager;
+import com.icegreen.greenmail.store.InMemoryStore;
+import com.icegreen.greenmail.store.Store;
+import com.icegreen.greenmail.user.UserManager;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.powermock.core.classloader.annotations.PrepareForTest;
+import org.powermock.modules.junit4.PowerMockRunner;
+
+import static org.hamcrest.Matchers.is;
+import static org.junit.Assert.assertThat;
+import static org.powermock.api.easymock.PowerMock.*;
+
+/**
+ * @author Raimund Klein <raimund.klein@gmx.de>
+ */
+@RunWith(PowerMockRunner.class)
+@PrepareForTest(Managers.class)
+public class ManagersTest {
+
+    @Test
+    public void shouldUseDefaultInMemoryStoreIfNoneGiven() throws Exception {
+        // Given
+        final InMemoryStore mockStore = createMockAndExpectNew(InMemoryStore.class);
+        replay(mockStore, InMemoryStore.class);
+
+        // When
+        new Managers();
+
+        // Then
+        verify(mockStore, InMemoryStore.class);
+    }
+
+    @Test
+    public void shouldCreateNewImapHostManagerImpl() throws Exception {
+        // Given
+        final Store store = new InMemoryStore();
+        final ImapHostManagerImpl mockHostManager = createMockAndExpectNew(ImapHostManagerImpl.class, store);
+        replay(mockHostManager, ImapHostManagerImpl.class);
+
+        // When
+        new Managers(store);
+
+        // Then
+        verify(mockHostManager, ImapHostManagerImpl.class);
+    }
+
+    @Test
+    public void shouldCreateNewUserManager() throws Exception {
+        // Given
+        final Store store = new InMemoryStore();
+        final ImapHostManagerImpl mockHostManager = createMock(ImapHostManagerImpl.class, store);
+        expectNew(ImapHostManagerImpl.class, store).andReturn(mockHostManager);
+        final UserManager mockUserManager = createMockAndExpectNew(UserManager.class, mockHostManager);
+        replay(mockHostManager, ImapHostManagerImpl.class, mockUserManager, UserManager.class);
+
+        // When
+        new Managers(store);
+
+        // Then
+        verify(mockUserManager, UserManager.class);
+    }
+
+    @Test
+    public void shouldCreateNewSmtpManager() throws Exception {
+        // Given
+        final Store store = new InMemoryStore();
+        final ImapHostManagerImpl mockHostManager = createMock(ImapHostManagerImpl.class, store);
+        expectNew(ImapHostManagerImpl.class, store).andReturn(mockHostManager);
+        final UserManager mockUserManager = createMock(UserManager.class, mockHostManager);
+        expectNew(UserManager.class, mockHostManager).andReturn(mockUserManager);
+        final SmtpManager mockSmtpManager = createMock(SmtpManager.class,
+                mockHostManager, mockUserManager);
+        replay(mockHostManager, ImapHostManagerImpl.class, mockUserManager, UserManager.class, mockSmtpManager,
+                SmtpManager.class);
+
+        // When
+        new Managers(store);
+
+        // Then
+        verify(mockSmtpManager, SmtpManager.class);
+    }
+
+    @Test
+    public void shouldCreateDefaultInMemoryStore() throws Exception {
+        // Given
+        final Managers managers = new Managers();
+        final Store mockStore = createMockAndExpectNew(InMemoryStore.class);
+        replay(mockStore, InMemoryStore.class);
+
+        // When
+        final Store createdStore = managers.createNewStore();
+
+        // Then
+        verify(mockStore, InMemoryStore.class);
+        assertThat(createdStore, is(mockStore));
+    }
+
+    @Test
+    public void shouldRecreateStoreAndAllSubManagers() throws Exception {
+        // Given
+        final Managers managers = new Managers();
+        final InMemoryStore mockStore = createMockAndExpectNew(InMemoryStore.class);
+        final ImapHostManagerImpl mockHostManager = createMockAndExpectNew(ImapHostManagerImpl.class, mockStore);
+        final UserManager mockUserManager = createMockAndExpectNew(UserManager.class, mockHostManager);
+        replay(mockStore, InMemoryStore.class, mockHostManager, ImapHostManagerImpl.class, mockUserManager,
+                UserManager.class);
+
+        // When
+        managers.reset();
+
+        // Then
+        verify(mockStore, InMemoryStore.class, mockHostManager, ImapHostManagerImpl.class, mockUserManager,
+                UserManager.class);
+    }
+}
\ No newline at end of file
diff --git a/greenmail-core/src/test/java/com/icegreen/greenmail/MemorySafeManagersTest.java b/greenmail-core/src/test/java/com/icegreen/greenmail/MemorySafeManagersTest.java
new file mode 100644
index 0000000000..0b36092154
--- /dev/null
+++ b/greenmail-core/src/test/java/com/icegreen/greenmail/MemorySafeManagersTest.java
@@ -0,0 +1,55 @@
+/*
+ *  -------------------------------------------------------------------
+ *  This software is released under the Apache license 2.0
+ *  -------------------------------------------------------------------
+ * /
+ */
+
+package com.icegreen.greenmail;
+
+import com.icegreen.greenmail.store.InMemoryStore;
+import com.icegreen.greenmail.store.Store;
+import com.icegreen.greenmail.store.StoredMessageCollectionFactory;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.powermock.core.classloader.annotations.PrepareForTest;
+import org.powermock.modules.junit4.PowerMockRunner;
+
+import static org.hamcrest.Matchers.is;
+import static org.junit.Assert.assertThat;
+import static org.powermock.api.easymock.PowerMock.*;
+
+/**
+ * @author Raimund Klein <raimund.klein@gmx.de>
+ */
+@RunWith(PowerMockRunner.class)
+@PrepareForTest(MemorySafeManagers.class)
+public class MemorySafeManagersTest {
+    @Test
+    public void shouldUseMapBasedFactoryInConstructor() throws Exception {
+        // Given
+        final InMemoryStore mockStore = createMockAndExpectNew(InMemoryStore.class, StoredMessageCollectionFactory.MAP_BASED_FACTORY);
+        replay(mockStore, InMemoryStore.class);
+
+        // When
+        new MemorySafeManagers();
+
+        // Then
+        verify(mockStore, InMemoryStore.class);
+    }
+
+    @Test
+    public void shouldCreateInMemoryStoreWithMapBasedFactory() throws Exception {
+        // Given
+        final Managers managers = new MemorySafeManagers();
+        final Store mockStore = createMockAndExpectNew(InMemoryStore.class, StoredMessageCollectionFactory.MAP_BASED_FACTORY);
+        replay(mockStore, InMemoryStore.class);
+
+        // When
+        final Store createdStore = managers.createNewStore();
+
+        // Then
+        verify(mockStore, InMemoryStore.class);
+        assertThat(createdStore, is(mockStore));
+    }
+}
\ No newline at end of file
diff --git a/greenmail-core/src/test/java/com/icegreen/greenmail/configuration/GreenMailConfigurationTest.java b/greenmail-core/src/test/java/com/icegreen/greenmail/configuration/GreenMailConfigurationTest.java
index 6452215a12..f4f7d61573 100644
--- a/greenmail-core/src/test/java/com/icegreen/greenmail/configuration/GreenMailConfigurationTest.java
+++ b/greenmail-core/src/test/java/com/icegreen/greenmail/configuration/GreenMailConfigurationTest.java
@@ -1,10 +1,14 @@
 package com.icegreen.greenmail.configuration;
 
+import com.icegreen.greenmail.Managers;
+import com.icegreen.greenmail.MemorySafeManagers;
 import com.icegreen.greenmail.util.GreenMail;
 import com.icegreen.greenmail.util.ServerSetupTest;
 import org.junit.Test;
 
+import static com.icegreen.greenmail.configuration.GreenMailConfigurationTestBase.testConfigWithMemorySafeManagers;
 import static com.icegreen.greenmail.configuration.GreenMailConfigurationTestBase.testUsersAccessibleConfig;
+import static org.junit.Assert.assertSame;
 
 /**
  * Tests if the configuration is applied correctly to GreenMail instances.
@@ -23,4 +27,28 @@ public void testUsersAccessible() {
         }
     }
 
+    @Test
+    public void shouldCreateManagersClassByDefault() {
+        // Given
+        final GreenMail greenMail = new GreenMail(ServerSetupTest.IMAP);
+
+        // When
+        final Managers managers = greenMail.createManagers();
+
+        // Then
+        assertSame(Managers.class, managers.getClass());
+    }
+
+    @Test
+    public void shouldCreateMemorySafeManagersWhenConfigured() {
+        // Given
+        final GreenMail greenMail = new GreenMail(ServerSetupTest.IMAP).withConfiguration
+                (testConfigWithMemorySafeManagers());
+
+        // When
+        final Managers managers = greenMail.createManagers();
+
+        // Then
+        assertSame(MemorySafeManagers.class, managers.getClass());
+    }
 }
\ No newline at end of file
diff --git a/greenmail-core/src/test/java/com/icegreen/greenmail/configuration/GreenMailConfigurationTestBase.java b/greenmail-core/src/test/java/com/icegreen/greenmail/configuration/GreenMailConfigurationTestBase.java
index a1788e7e82..04c2ddb74d 100644
--- a/greenmail-core/src/test/java/com/icegreen/greenmail/configuration/GreenMailConfigurationTestBase.java
+++ b/greenmail-core/src/test/java/com/icegreen/greenmail/configuration/GreenMailConfigurationTestBase.java
@@ -1,5 +1,6 @@
 package com.icegreen.greenmail.configuration;
 
+import com.icegreen.greenmail.MemorySafeManagers;
 import com.icegreen.greenmail.base.GreenMailOperations;
 import com.icegreen.greenmail.util.Retriever;
 
@@ -45,4 +46,11 @@ public static GreenMailConfiguration testUsersAccessibleConfig() {
                 .withUser("user@localhost", "password")
                 .withUser("secondUser@localhost", "secondUserLogin", "password2");
     }
+
+    /**
+     * @return A {@link GreenMailConfiguration} with {@link MemorySafeManagers} as Managers class.
+     */
+    public static GreenMailConfiguration testConfigWithMemorySafeManagers() {
+        return aConfig().withManagersClass(MemorySafeManagers.class);
+    }
 }
diff --git a/greenmail-core/src/test/java/com/icegreen/greenmail/imap/ImapHostManagerImplTest.java b/greenmail-core/src/test/java/com/icegreen/greenmail/imap/ImapHostManagerImplTest.java
new file mode 100644
index 0000000000..f786c54c02
--- /dev/null
+++ b/greenmail-core/src/test/java/com/icegreen/greenmail/imap/ImapHostManagerImplTest.java
@@ -0,0 +1,34 @@
+/* -------------------------------------------------------------------
+* This software is released under the Apache license 2.0
+* -------------------------------------------------------------------
+*/
+package com.icegreen.greenmail.imap;
+
+import com.icegreen.greenmail.store.InMemoryStore;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.powermock.core.classloader.annotations.PrepareForTest;
+import org.powermock.modules.junit4.PowerMockRunner;
+
+import static org.powermock.api.easymock.PowerMock.*;
+
+/**
+ * @author Raimund Klein <raimund.klein@gmx.de>
+ */
+@RunWith(PowerMockRunner.class)
+@PrepareForTest(ImapHostManagerImpl.class)
+public class ImapHostManagerImplTest {
+
+    @Test
+    public void shouldUseDefaultInMemoryStoreIfNoneGiven() throws Exception {
+        // Given
+        final InMemoryStore mockStore = createMockAndExpectNew(InMemoryStore.class);
+        replay(mockStore, InMemoryStore.class);
+
+        // When
+        new ImapHostManagerImpl();
+
+        // Then
+        verify(mockStore, InMemoryStore.class);
+    }
+}
\ No newline at end of file
diff --git a/greenmail-core/src/test/java/com/icegreen/greenmail/store/InMemoryStoreTest.java b/greenmail-core/src/test/java/com/icegreen/greenmail/store/InMemoryStoreTest.java
new file mode 100644
index 0000000000..7b0d3a12df
--- /dev/null
+++ b/greenmail-core/src/test/java/com/icegreen/greenmail/store/InMemoryStoreTest.java
@@ -0,0 +1,49 @@
+/* -------------------------------------------------------------------
+* This software is released under the Apache license 2.0
+* -------------------------------------------------------------------
+*/
+package com.icegreen.greenmail.store;
+
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.powermock.core.classloader.annotations.PrepareForTest;
+import org.powermock.modules.junit4.PowerMockRunner;
+
+import static org.powermock.api.easymock.PowerMock.*;
+
+/**
+ * @author Raimund Klein <raimund.klein@gmx.de>
+ */
+@RunWith(PowerMockRunner.class)
+@PrepareForTest(InMemoryStore.class)
+public class InMemoryStoreTest {
+    @Test
+    public void shouldUsedListBasedFactoryByDefault() throws Exception {
+        // Given
+        final RootFolder mockFolder = createMockAndExpectNew(RootFolder.class, StoredMessageCollectionFactory
+                .LIST_BASED_FACTORY);
+        replay(mockFolder, RootFolder.class);
+
+        // When
+        new InMemoryStore();
+
+        // Then
+        verify(mockFolder, RootFolder.class);
+    }
+
+    @Test
+    public void shouldForwardGivenFactory() throws Exception {
+        for (final StoredMessageCollectionFactory factory : StoredMessageCollectionFactory.values()) {
+            // Given
+            final RootFolder mockFolder = createMockAndExpectNew(RootFolder.class, factory);
+            replay(mockFolder, RootFolder.class);
+
+            // When
+            new InMemoryStore(factory);
+
+            // Then
+            verify(mockFolder, RootFolder.class);
+            reset(RootFolder.class);
+        }
+    }
+}
\ No newline at end of file
diff --git a/greenmail-core/src/test/java/com/icegreen/greenmail/store/StoredMessageCollectionFactoryPowerMockTest.java b/greenmail-core/src/test/java/com/icegreen/greenmail/store/StoredMessageCollectionFactoryPowerMockTest.java
new file mode 100644
index 0000000000..50a40ab791
--- /dev/null
+++ b/greenmail-core/src/test/java/com/icegreen/greenmail/store/StoredMessageCollectionFactoryPowerMockTest.java
@@ -0,0 +1,66 @@
+/*
+ *  -------------------------------------------------------------------
+ *  This software is released under the Apache license 2.0
+ *  -------------------------------------------------------------------
+ * /
+ */
+
+package com.icegreen.greenmail.store;
+
+import org.hamcrest.Matchers;
+import org.junit.Ignore;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.powermock.core.classloader.annotations.PrepareForTest;
+import org.powermock.modules.junit4.PowerMockRunner;
+
+import static org.hamcrest.Matchers.is;
+import static org.junit.Assert.assertThat;
+import static org.powermock.api.easymock.PowerMock.*;
+
+/**
+ * @author Raimund Klein <raimund.klein@gmx.de>
+ */
+@RunWith(PowerMockRunner.class)
+@PrepareForTest(StoredMessageCollectionFactory.class)
+public class StoredMessageCollectionFactoryPowerMockTest {
+    // The following tests require a fix for PowerMock issue #552:
+    // https://code.google.com/p/powermock/issues/detail?id=552
+
+    @Test
+    @Ignore
+    public void shouldCreateMapBasedCollectionWithSize5000ByDefault() throws Exception {
+        // Given
+        final MapBasedStoredMessageCollection mockCollection = createMockAndExpectNew(MapBasedStoredMessageCollection
+                .class, new Class<?>[]{int.class}, 5000);
+        replay(mockCollection, MapBasedStoredMessageCollection.class);
+
+        // When
+        final StoredMessageCollection createdCollection = StoredMessageCollectionFactory.MAP_BASED_FACTORY
+                .createCollection();
+
+        // Then
+        assertThat(createdCollection, is(Matchers.<StoredMessageCollection>sameInstance(mockCollection)));
+        verify(mockCollection, MapBasedStoredMessageCollection.class);
+    }
+
+    @Test
+    @Ignore
+    public void shouldCreateMapBasedCollectionWithGivenSizeIfPropertyIsSet() throws Exception {
+        // Given
+        final int expectedMapSize = 200;
+        StoredMessageCollectionFactory.MAP_BASED_FACTORY.withConfigurationValue(StoredMessageCollectionFactory
+                .Constants.CONFIGURATION_KEY_MAXIMUM_MAP_SIZE, expectedMapSize);
+        final MapBasedStoredMessageCollection mockCollection = createMockAndExpectNew(MapBasedStoredMessageCollection
+                .class, new Class<?>[]{int.class}, expectedMapSize);
+        replay(mockCollection, MapBasedStoredMessageCollection.class);
+
+        // When
+        final StoredMessageCollection createdCollection = StoredMessageCollectionFactory.MAP_BASED_FACTORY
+                .createCollection();
+
+        // Then
+        assertThat(createdCollection, is(Matchers.<StoredMessageCollection>sameInstance(mockCollection)));
+        verify(mockCollection, MapBasedStoredMessageCollection.class);
+    }
+}
diff --git a/greenmail-core/src/test/java/com/icegreen/greenmail/store/StoredMessageCollectionFactoryTest.java b/greenmail-core/src/test/java/com/icegreen/greenmail/store/StoredMessageCollectionFactoryTest.java
new file mode 100644
index 0000000000..bef9bd198c
--- /dev/null
+++ b/greenmail-core/src/test/java/com/icegreen/greenmail/store/StoredMessageCollectionFactoryTest.java
@@ -0,0 +1,60 @@
+/* -------------------------------------------------------------------
+* This software is released under the Apache license 2.0
+* -------------------------------------------------------------------
+*/
+package com.icegreen.greenmail.store;
+
+import org.hamcrest.Matchers;
+import org.junit.Test;
+import org.junit.experimental.theories.DataPoints;
+import org.junit.experimental.theories.Theories;
+import org.junit.experimental.theories.Theory;
+import org.junit.runner.RunWith;
+
+import static org.hamcrest.Matchers.is;
+import static org.junit.Assert.assertThat;
+import static org.junit.Assert.fail;
+
+/**
+ * @author Raimund Klein <raimund.klein@gmx.de>
+ */
+@RunWith(Theories.class)
+public class StoredMessageCollectionFactoryTest {
+    @DataPoints
+    public static FactoryWithMatchingClass[] createFactoryPoints() {
+        return new FactoryWithMatchingClass[]{
+                new FactoryWithMatchingClass(StoredMessageCollectionFactory.LIST_BASED_FACTORY, ListBasedStoredMessageCollection.class),
+                new FactoryWithMatchingClass(StoredMessageCollectionFactory.MAP_BASED_FACTORY, MapBasedStoredMessageCollection.class)};
+    }
+
+    @Theory
+    public void shouldCreateMatchingCollection(final FactoryWithMatchingClass factoryWithMatchingClass) {
+        // When
+        final StoredMessageCollection collection = factoryWithMatchingClass.factory.createCollection();
+
+        // Then
+        assertThat(collection, is(Matchers.<StoredMessageCollection>instanceOf(factoryWithMatchingClass.collectionClass)));
+    }
+
+    private static class FactoryWithMatchingClass {
+        private final StoredMessageCollectionFactory factory;
+        private final Class<? extends StoredMessageCollection> collectionClass;
+
+        private FactoryWithMatchingClass(StoredMessageCollectionFactory factory, Class<? extends StoredMessageCollection> collectionClass) {
+            this.factory = factory;
+            this.collectionClass = collectionClass;
+        }
+    }
+
+    @Test
+    public void shouldRejectUnknownProperty() {
+        for (final StoredMessageCollectionFactory factory : StoredMessageCollectionFactory.values()) {
+            try {
+                factory.withConfigurationValue("foo", "bar");
+                fail("Should have thrown exception");
+            } catch (IllegalArgumentException e) {
+                // This is expected.
+            }
+        }
+    }
+}
\ No newline at end of file
diff --git a/greenmail-core/src/test/java/com/icegreen/greenmail/test/GreenMailUtilTest.java b/greenmail-core/src/test/java/com/icegreen/greenmail/test/GreenMailUtilTest.java
index 42888c1086..e155f7f095 100644
--- a/greenmail-core/src/test/java/com/icegreen/greenmail/test/GreenMailUtilTest.java
+++ b/greenmail-core/src/test/java/com/icegreen/greenmail/test/GreenMailUtilTest.java
@@ -25,6 +25,26 @@
  * @since Jan 29, 2006
  */
 public class GreenMailUtilTest {
+    final static String SAMPLE_EMAIL = "From - Thu Jan 19 00:30:34 2006\r\n"
+            + "X-Account-Key: account245\r\n"
+            + "X-UIDL: 11332317636080.2607.mail5,S=833\r\n"
+            + "X-Mozilla-Status: 0001\r\n"
+            + "X-Mozilla-Status2: 00000000\r\n"
+            + "Return-Path: <bertil@surstomming.com>\r\n"
+            + "Delivered-To: eivar@blastigen.com\r\n"
+            + "Received: (qmail 2376 invoked from network); 19 Jan 2006 02:01:05 -0000\r\n"
+            + "Received: from unknown (HELO [192.168.0.5]) (hej@66.245.216.76)\r\n"
+            + "\tby mail5.hotmail.com with (RC4-MD5 encrypted) SMTP; Wed, 18 Jan 2006 18:01:05 -0800\r\n"
+            + "Message-ID: <43CEF322.7080702@hotmail.com>\r\n"
+            + "Date: Wed, 18 Jan 2006 18:02:10 -0800\r\n"
+            + "From: Wael Chatila <wael@localhost.com>\r\n"
+            + "User-Agent: Mozilla Thunderbird 1.0.7 (Windows/20050923)\r\n"
+            + "X-Accept-Language: en-us, en\r\n" + "MIME-Version: 1.0\r\n"
+            + "To: Bertil <bertil@localhost.com>\r\n" + "Subject: wassup\r\n"
+            + "Content-Type: text/plain; charset=ISO-8859-1; format=flowed\r\n"
+            + "Content-Transfer-Encoding: 7bit\r\n" + "\r\n"
+            + "Yo wassup Bertil\r\n";
+
     @Test
     public void testMimeMessageLoading() throws MessagingException {
         MimeMessage message = GreenMailUtil.newMimeMessage(SAMPLE_EMAIL);
@@ -101,24 +121,4 @@ public void testSetAndGetQuota() throws MessagingException {
             greenMail.stop();
         }
     }
-
-    final static String SAMPLE_EMAIL = "From - Thu Jan 19 00:30:34 2006\r\n"
-            + "X-Account-Key: account245\r\n"
-            + "X-UIDL: 11332317636080.2607.mail5,S=833\r\n"
-            + "X-Mozilla-Status: 0001\r\n"
-            + "X-Mozilla-Status2: 00000000\r\n"
-            + "Return-Path: <bertil@surstomming.com>\r\n"
-            + "Delivered-To: eivar@blastigen.com\r\n"
-            + "Received: (qmail 2376 invoked from network); 19 Jan 2006 02:01:05 -0000\r\n"
-            + "Received: from unknown (HELO [192.168.0.5]) (hej@66.245.216.76)\r\n"
-            + "\tby mail5.hotmail.com with (RC4-MD5 encrypted) SMTP; Wed, 18 Jan 2006 18:01:05 -0800\r\n"
-            + "Message-ID: <43CEF322.7080702@hotmail.com>\r\n"
-            + "Date: Wed, 18 Jan 2006 18:02:10 -0800\r\n"
-            + "From: Wael Chatila <wael@localhost.com>\r\n"
-            + "User-Agent: Mozilla Thunderbird 1.0.7 (Windows/20050923)\r\n"
-            + "X-Accept-Language: en-us, en\r\n" + "MIME-Version: 1.0\r\n"
-            + "To: Bertil <bertil@localhost.com>\r\n" + "Subject: wassup\r\n"
-            + "Content-Type: text/plain; charset=ISO-8859-1; format=flowed\r\n"
-            + "Content-Transfer-Encoding: 7bit\r\n" + "\r\n"
-            + "Yo wassup Bertil\r\n";
 }
diff --git a/greenmail-core/src/test/java/com/icegreen/greenmail/test/ServerStartStopTest.java b/greenmail-core/src/test/java/com/icegreen/greenmail/test/ServerStartStopTest.java
index ec02192e26..54c4e97dff 100644
--- a/greenmail-core/src/test/java/com/icegreen/greenmail/test/ServerStartStopTest.java
+++ b/greenmail-core/src/test/java/com/icegreen/greenmail/test/ServerStartStopTest.java
@@ -53,7 +53,7 @@ public void testServerStartupTimeout() {
         }
 
         // Set large startup timeout
-        for(ServerSetup s: setups) {
+        for (ServerSetup s : setups) {
             s.setServerStartupTimeout(3000L);
         }
         service = new GreenMail(setups);
diff --git a/greenmail-core/src/test/resources/log4j.xml b/greenmail-core/src/test/resources/log4j.xml
index 2d7728a79c..553a61dd01 100644
--- a/greenmail-core/src/test/resources/log4j.xml
+++ b/greenmail-core/src/test/resources/log4j.xml
@@ -26,7 +26,7 @@
   </appender>
 
   <root>
-    <level value="TRACE" />
+    <level value="TRACE"/>
     <appender-ref ref="CONSOLE"/>
     <appender-ref ref="FILE"/>
   </root>
diff --git a/greenmail-site/index.html b/greenmail-site/index.html
index 77a77d4c47..b2cfc7f26f 100644
--- a/greenmail-site/index.html
+++ b/greenmail-site/index.html
@@ -745,16 +745,18 @@ <h4>How can I use IMAP quotas?</h4>
                     ImapServerTest.java</a> quota test</p>
 
                 <h4>How can I create or delete a mail user?</h4>
+
                 <p>
 <pre><code class="language-java"><!-- @formatter:off -->
-GreenMail greenMail = ...
-// Create user with login id equals email
-GreenMailUser user1 = greenMail.setUser("foo@localhost", "some secret pwd");
-// Create user with login id different than email
-GreenMailUser user2 = greenMail.setUser("foo@localhost", "login-id", "some secret pwd");
-...
-greenMail.getManagers().getUserManager().deleteUser(user1); // Delete user
-</code></pre><!-- @formatter:on -->
+                GreenMail greenMail = ...
+                // Create user with login id equals email
+                GreenMailUser user1 = greenMail.setUser("foo@localhost", "some secret pwd");
+                // Create user with login id different than email
+                GreenMailUser user2 = greenMail.setUser("foo@localhost", "login-id", "some secret pwd");
+                ...
+                greenMail.getManagers().getUserManager().deleteUser(user1); // Delete user
+            </code></pre>
+                <!-- @formatter:on -->
                 </p>
 
             </div>
diff --git a/pom.xml b/pom.xml
index c613cef6ca..6a1ae80b02 100644
--- a/pom.xml
+++ b/pom.xml
@@ -253,6 +253,7 @@
   <properties>
     <slf4j.version>1.7.12</slf4j.version>
     <hamcrest.version>1.3</hamcrest.version>
+    <powermock.version>1.6.3</powermock.version>
     <spring.version>4.1.7.RELEASE</spring.version>
     <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
     <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
@@ -365,6 +366,18 @@
         <version>3.2</version>
         <scope>test</scope>
       </dependency>
+      <dependency>
+        <groupId>org.powermock</groupId>
+        <artifactId>powermock-module-junit4</artifactId>
+        <version>${powermock.version}</version>
+        <scope>test</scope>
+      </dependency>
+      <dependency>
+        <groupId>org.powermock</groupId>
+        <artifactId>powermock-api-easymock</artifactId>
+        <version>${powermock.version}</version>
+        <scope>test</scope>
+      </dependency>
       <dependency>
         <groupId>org.hamcrest</groupId>
         <artifactId>hamcrest-core</artifactId>