diff --git a/src/main/scala/app/IndexController.scala b/src/main/scala/app/IndexController.scala
index 2925e8c..1959463 100644
--- a/src/main/scala/app/IndexController.scala
+++ b/src/main/scala/app/IndexController.scala
@@ -59,6 +59,10 @@
     session.setAttribute(Keys.Session.LoginAccount, account)
     updateLastLoginDate(account.userName)
 
+    if(AccountUtil.hasLdapDummyMailAddress(account)) {
+      redirect("/" + account.userName + "/_edit")
+    }
+
     flash.get(Keys.Flash.Redirect).asInstanceOf[Option[String]].map { redirectUrl =>
       if(redirectUrl.stripSuffix("/") == request.getContextPath){
         redirect("/")
diff --git a/src/main/scala/app/SystemSettingsController.scala b/src/main/scala/app/SystemSettingsController.scala
index da30699..c5cf523 100644
--- a/src/main/scala/app/SystemSettingsController.scala
+++ b/src/main/scala/app/SystemSettingsController.scala
@@ -41,8 +41,9 @@
         "bindPassword"             -> trim(label("Bind Password", optional(text()))),
         "baseDN"                   -> trim(label("Base DN", text(required))),
         "userNameAttribute"        -> trim(label("User name attribute", text(required))),
+        "additionalFilterCondition"-> trim(label("Additional filter condition", optional(text()))),
         "fullNameAttribute"        -> trim(label("Full name attribute", optional(text()))),
-        "mailAttribute"            -> trim(label("Mail address attribute", text(required))),
+        "mailAttribute"            -> trim(label("Mail address attribute", optional(text()))),
         "tls"                      -> trim(label("Enable TLS", optional(boolean()))),
         "keystore"                 -> trim(label("Keystore", optional(text())))
     )(Ldap.apply))
diff --git a/src/main/scala/service/AccountService.scala b/src/main/scala/service/AccountService.scala
index 7472738..ad0d363 100644
--- a/src/main/scala/service/AccountService.scala
+++ b/src/main/scala/service/AccountService.scala
@@ -39,7 +39,11 @@
         // Create or update account by LDAP information
         getAccountByUserName(ldapUserInfo.userName, true) match {
           case Some(x) if(!x.isRemoved) => {
-            updateAccount(x.copy(mailAddress = ldapUserInfo.mailAddress, fullName = ldapUserInfo.fullName))
+            if(settings.ldap.get.mailAttribute.getOrElse("").isEmpty) {
+              updateAccount(x.copy(fullName = ldapUserInfo.fullName))
+            } else {
+              updateAccount(x.copy(mailAddress = ldapUserInfo.mailAddress, fullName = ldapUserInfo.fullName))
+            }
             getAccountByUserName(ldapUserInfo.userName)
           }
           case Some(x) if(x.isRemoved)  => {
diff --git a/src/main/scala/service/SystemSettingsService.scala b/src/main/scala/service/SystemSettingsService.scala
index 42f3a75..2d8f1d3 100644
--- a/src/main/scala/service/SystemSettingsService.scala
+++ b/src/main/scala/service/SystemSettingsService.scala
@@ -37,8 +37,9 @@
           ldap.bindPassword.foreach(x => props.setProperty(LdapBindPassword, x))
           props.setProperty(LdapBaseDN, ldap.baseDN)
           props.setProperty(LdapUserNameAttribute, ldap.userNameAttribute)
+          ldap.additionalFilterCondition.foreach(x => props.setProperty(LdapAdditionalFilterCondition, x))
           ldap.fullNameAttribute.foreach(x => props.setProperty(LdapFullNameAttribute, x))
-          props.setProperty(LdapMailAddressAttribute, ldap.mailAttribute)
+          ldap.mailAttribute.foreach(x => props.setProperty(LdapMailAddressAttribute, x.toString))
           ldap.tls.foreach(x => props.setProperty(LdapTls, x.toString))
           ldap.keystore.foreach(x => props.setProperty(LdapKeystore, x))
         }
@@ -85,8 +86,9 @@
             getOptionValue(props, LdapBindPassword, None),
             getValue(props, LdapBaseDN, ""),
             getValue(props, LdapUserNameAttribute, ""),
+            getOptionValue(props, LdapAdditionalFilterCondition, None),
             getOptionValue(props, LdapFullNameAttribute, None),
-            getValue(props, LdapMailAddressAttribute, ""),
+            getOptionValue(props, LdapMailAddressAttribute, None),
             getOptionValue[Boolean](props, LdapTls, None),
             getOptionValue(props, LdapKeystore, None)))
         } else {
@@ -125,8 +127,9 @@
     bindPassword: Option[String],
     baseDN: String,
     userNameAttribute: String,
+    additionalFilterCondition: Option[String],
     fullNameAttribute: Option[String],
-    mailAttribute: String,
+    mailAttribute: Option[String],
     tls: Option[Boolean],
     keystore: Option[String])
 
@@ -163,6 +166,7 @@
   private val LdapBindPassword = "ldap.bind_password"
   private val LdapBaseDN = "ldap.baseDN"
   private val LdapUserNameAttribute = "ldap.username_attribute"
+  private val LdapAdditionalFilterCondition = "ldap.additional_filter_condition"
   private val LdapFullNameAttribute = "ldap.fullname_attribute"
   private val LdapMailAddressAttribute = "ldap.mail_attribute"
   private val LdapTls = "ldap.tls"
diff --git a/src/main/scala/util/AccountUtil.scala b/src/main/scala/util/AccountUtil.scala
new file mode 100644
index 0000000..e6da429
--- /dev/null
+++ b/src/main/scala/util/AccountUtil.scala
@@ -0,0 +1,18 @@
+package util
+
+import model.Account
+
+/**
+ * Utility for account model.
+ */
+object AccountUtil {
+  private val LDAP_DUMMY_MAL = "@ldap-devnull"
+
+  def hasLdapDummyMailAddress(account: Account): Boolean = {
+    account.mailAddress.endsWith(LDAP_DUMMY_MAL)
+  }
+
+  def getLdapDummyMailAddress(userName: String): String = {
+    userName + LDAP_DUMMY_MAL
+  }
+}
diff --git a/src/main/scala/util/LDAPUtil.scala b/src/main/scala/util/LDAPUtil.scala
index d107b96..621fbd5 100644
--- a/src/main/scala/util/LDAPUtil.scala
+++ b/src/main/scala/util/LDAPUtil.scala
@@ -30,7 +30,7 @@
       keystore = ldapSettings.keystore.getOrElse(""),
       error    = "System LDAP authentication failed."
     ){ conn =>
-      findUser(conn, userName, ldapSettings.baseDN, ldapSettings.userNameAttribute) match {
+      findUser(conn, userName, ldapSettings.baseDN, ldapSettings.userNameAttribute, ldapSettings.additionalFilterCondition) match {
         case Some(userDN) => userAuthentication(ldapSettings, userDN, userName, password)
         case None         => Left("User does not exist.")
       }
@@ -47,14 +47,23 @@
       keystore = ldapSettings.keystore.getOrElse(""),
       error    = "User LDAP Authentication Failed."
     ){ conn =>
-      findMailAddress(conn, userDN, ldapSettings.userNameAttribute, userName, ldapSettings.mailAttribute) match {
-        case Some(mailAddress) => Right(LDAPUserInfo(
-          userName    = getUserNameFromMailAddress(userName),
+      if(ldapSettings.mailAttribute.getOrElse("").isEmpty) {
+        Right(LDAPUserInfo(
+          userName    = userName,
           fullName    = ldapSettings.fullNameAttribute.flatMap { fullNameAttribute =>
             findFullName(conn, userDN, ldapSettings.userNameAttribute, userName, fullNameAttribute)
           }.getOrElse(userName),
-          mailAddress = mailAddress))
-        case None => Left("Can't find mail address.")
+          mailAddress = AccountUtil.getLdapDummyMailAddress(userName)))
+      } else {
+        findMailAddress(conn, userDN, ldapSettings.userNameAttribute, userName, ldapSettings.mailAttribute.get) match {
+          case Some(mailAddress) => Right(LDAPUserInfo(
+            userName    = getUserNameFromMailAddress(userName),
+            fullName    = ldapSettings.fullNameAttribute.flatMap { fullNameAttribute =>
+              findFullName(conn, userDN, ldapSettings.userNameAttribute, userName, fullNameAttribute)
+            }.getOrElse(userName),
+            mailAddress = mailAddress))
+          case None => Left("Can't find mail address.")
+        }
       }
     }
   }
@@ -112,7 +121,7 @@
   /**
    * Search a specified user and returns userDN if exists.
    */
-  private def findUser(conn: LDAPConnection, userName: String, baseDN: String, userNameAttribute: String): Option[String] = {
+  private def findUser(conn: LDAPConnection, userName: String, baseDN: String, userNameAttribute: String, additionalFilterCondition: Option[String]): Option[String] = {
     @tailrec
     def getEntries(results: LDAPSearchResults, entries: List[Option[LDAPEntry]] = Nil): List[LDAPEntry] = {
       if(results.hasMore){
@@ -125,7 +134,13 @@
         entries.flatten
       }
     }
-    getEntries(conn.search(baseDN, LDAPConnection.SCOPE_SUB, userNameAttribute + "=" + userName, null, false)).collectFirst {
+
+    val filterCond = additionalFilterCondition.getOrElse("") match {
+      case "" => userNameAttribute + "=" + userName
+      case x => "(&(" + x + ")(" + userNameAttribute + "=" + userName + "))"
+    }
+
+    getEntries(conn.search(baseDN, LDAPConnection.SCOPE_SUB, filterCond, null, false)).collectFirst {
       case x => x.getDN
     }
   }
diff --git a/src/main/scala/util/Notifier.scala b/src/main/scala/util/Notifier.scala
index e1bd50b..e218800 100644
--- a/src/main/scala/util/Notifier.scala
+++ b/src/main/scala/util/Notifier.scala
@@ -28,7 +28,7 @@
     )
     .distinct
     .withFilter ( _ != context.loginAccount.get.userName )	// the operation in person is excluded
-    .foreach ( getAccountByUserName(_) filterNot (_.isGroupAccount) foreach (x => notify(x.mailAddress)) )
+    .foreach ( getAccountByUserName(_) filterNot (_.isGroupAccount) filterNot (AccountUtil.hasLdapDummyMailAddress(_)) foreach (x => notify(x.mailAddress)) )
 
 }
 
diff --git a/src/main/twirl/account/edit.scala.html b/src/main/twirl/account/edit.scala.html
index d92c708..a441f09 100644
--- a/src/main/twirl/account/edit.scala.html
+++ b/src/main/twirl/account/edit.scala.html
@@ -1,6 +1,7 @@
 @(account: model.Account, info: Option[Any])(implicit context: app.Context)
 @import context._
 @import view.helpers._
+@import util.AccountUtil
 @html.main("Edit your profile"){
 <div class="container">
   <div class="row-fluid">
@@ -9,6 +10,7 @@
     </div>
     <div class="span9">
       @helper.html.information(info)
+      @if(AccountUtil.hasLdapDummyMailAddress(account)){<div class="alert alert-danger">Please register your mail address.</div>}
       <form action="@url(account.userName)/_edit" method="POST" validate="true">
       <div class="box">
         <div class="box-header">Profile</div>
@@ -31,7 +33,7 @@
               </fieldset>
               <fieldset>
                 <label for="mailAddress" class="strong">Mail Address:</label>
-                <input type="text" name="mailAddress" id="mailAddress" value="@account.mailAddress"/>
+                <input type="text" name="mailAddress" id="mailAddress" value="@if(!AccountUtil.hasLdapDummyMailAddress(account)){@account.mailAddress}"/>
                 <span id="error-mailAddress" class="error"></span>
               </fieldset>
               <fieldset>
@@ -52,7 +54,7 @@
               <a href="@path/@account.userName/_delete" class="btn btn-danger" id="delete">Delete account</a>
             </div>
             <input type="submit" class="btn btn-success" value="Save"/>
-            <a href="@url(account.userName)" class="btn">Cancel</a>
+            @if(!AccountUtil.hasLdapDummyMailAddress(account)){<a href="@url(account.userName)" class="btn">Cancel</a>}
           </div>
         </div>
       </div>
@@ -66,4 +68,4 @@
     return confirm('Once you delete your account, there is no going back.\nAre you sure?');
   });
 });
-</script>
\ No newline at end of file
+</script>
diff --git a/src/main/twirl/admin/system.scala.html b/src/main/twirl/admin/system.scala.html
index 13a247d..3ef154f 100644
--- a/src/main/twirl/admin/system.scala.html
+++ b/src/main/twirl/admin/system.scala.html
@@ -134,6 +134,13 @@
               </div>
             </div>
             <div class="control-group">
+              <label class="control-label" for="ldapAdditionalFilterCondition">Additional filter condition</label>
+              <div class="controls">
+                <input type="text" id="ldapAdditionalFilterCondition" name="ldap.additionalFilterCondition" value="@settings.ldap.map(_.additionalFilterCondition)"/>
+                <span id="error-ldap_additionalFilterCondition" class="error"></span>
+              </div>
+            </div>
+            <div class="control-group">
               <label class="control-label" for="ldapFullNameAttribute">Full name attribute</label>
               <div class="controls">
                 <input type="text" id="ldapFullNameAttribute" name="ldap.fullNameAttribute" value="@settings.ldap.map(_.fullNameAttribute)"/>