diff --git a/src/main/scala/app/IndexController.scala b/src/main/scala/app/IndexController.scala
index 1959463..54d5b93 100644
--- a/src/main/scala/app/IndexController.scala
+++ b/src/main/scala/app/IndexController.scala
@@ -59,7 +59,7 @@
     session.setAttribute(Keys.Session.LoginAccount, account)
     updateLastLoginDate(account.userName)
 
-    if(AccountUtil.hasLdapDummyMailAddress(account)) {
+    if(LDAPUtil.hasLdapDummyMailAddress(account)) {
       redirect("/" + account.userName + "/_edit")
     }
 
diff --git a/src/main/scala/util/AccountUtil.scala b/src/main/scala/util/AccountUtil.scala
deleted file mode 100644
index e6da429..0000000
--- a/src/main/scala/util/AccountUtil.scala
+++ /dev/null
@@ -1,18 +0,0 @@
-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 621fbd5..00dd50b 100644
--- a/src/main/scala/util/LDAPUtil.scala
+++ b/src/main/scala/util/LDAPUtil.scala
@@ -7,6 +7,7 @@
 import org.slf4j.LoggerFactory
 import service.SystemSettingsService.Ldap
 import scala.annotation.tailrec
+import model.Account
 
 /**
  * Utility for LDAP authentication.
@@ -16,6 +17,26 @@
   private val LDAP_VERSION: Int = LDAPConnection.LDAP_V3
   private val logger = LoggerFactory.getLogger(getClass().getName())
 
+  private val LDAP_DUMMY_MAL = "@ldap-devnull"
+
+  /**
+   * Returns true if mail address ends with "@ldap-devnull"
+   */
+  def hasLdapDummyMailAddress(account: Account): Boolean = {
+    account.mailAddress.endsWith(LDAP_DUMMY_MAL)
+  }
+
+  /**
+   * Creates dummy address (userName@ldap-devnull) for LDAP login.
+   *
+   * If  mail address is not managed in LDAP server, GitBucket stores this dummy address in first LDAP login.
+   * GitBucket does not send any mails to this dummy address. And these users must input their mail address
+   * at the first step after LDAP authentication.
+   */
+  def getLdapDummyMailAddress(userName: String): String = {
+    userName + LDAP_DUMMY_MAL
+  }
+
   /**
    * Try authentication by LDAP using given configuration.
    * Returns Right(LDAPUserInfo) if authentication is successful, otherwise  Left(errorMessage).
@@ -53,7 +74,7 @@
           fullName    = ldapSettings.fullNameAttribute.flatMap { fullNameAttribute =>
             findFullName(conn, userDN, ldapSettings.userNameAttribute, userName, fullNameAttribute)
           }.getOrElse(userName),
-          mailAddress = AccountUtil.getLdapDummyMailAddress(userName)))
+          mailAddress = getLdapDummyMailAddress(userName)))
       } else {
         findMailAddress(conn, userDN, ldapSettings.userNameAttribute, userName, ldapSettings.mailAttribute.get) match {
           case Some(mailAddress) => Right(LDAPUserInfo(
diff --git a/src/main/scala/util/Notifier.scala b/src/main/scala/util/Notifier.scala
index e218800..6ecc3f6 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) filterNot (AccountUtil.hasLdapDummyMailAddress(_)) foreach (x => notify(x.mailAddress)) )
+    .foreach ( getAccountByUserName(_) filterNot (_.isGroupAccount) filterNot (LDAPUtil.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 a441f09..599c453 100644
--- a/src/main/twirl/account/edit.scala.html
+++ b/src/main/twirl/account/edit.scala.html
@@ -1,7 +1,7 @@
 @(account: model.Account, info: Option[Any])(implicit context: app.Context)
 @import context._
 @import view.helpers._
-@import util.AccountUtil
+@import util.LDAPUtil
 @html.main("Edit your profile"){
 <div class="container">
   <div class="row-fluid">
@@ -10,7 +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>}
+      @if(LDAPUtil.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>
@@ -33,7 +33,7 @@
               </fieldset>
               <fieldset>
                 <label for="mailAddress" class="strong">Mail Address:</label>
-                <input type="text" name="mailAddress" id="mailAddress" value="@if(!AccountUtil.hasLdapDummyMailAddress(account)){@account.mailAddress}"/>
+                <input type="text" name="mailAddress" id="mailAddress" value="@if(!LDAPUtil.hasLdapDummyMailAddress(account)){@account.mailAddress}"/>
                 <span id="error-mailAddress" class="error"></span>
               </fieldset>
               <fieldset>
@@ -54,7 +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"/>
-            @if(!AccountUtil.hasLdapDummyMailAddress(account)){<a href="@url(account.userName)" class="btn">Cancel</a>}
+            @if(!LDAPUtil.hasLdapDummyMailAddress(account)){<a href="@url(account.userName)" class="btn">Cancel</a>}
           </div>
         </div>
       </div>