diff --git a/src/main/scala/app/SystemSettingsController.scala b/src/main/scala/app/SystemSettingsController.scala
index 3d30aff..a2e410e 100644
--- a/src/main/scala/app/SystemSettingsController.scala
+++ b/src/main/scala/app/SystemSettingsController.scala
@@ -35,8 +35,7 @@
         "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))),
-        "disableMailResolve"       -> trim(label("Disable Mail Resolve", optional(boolean()))),
+        "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 1b021ea..d248c89 100644
--- a/src/main/scala/service/AccountService.scala
+++ b/src/main/scala/service/AccountService.scala
@@ -40,7 +40,7 @@
         // Create or update account by LDAP information
         getAccountByUserName(userName, true) match {
           case Some(x) if(!x.isRemoved) => {
-            if(settings.ldap.get.disableMailResolve.getOrElse(false)) {
+            if(settings.ldap.get.mailAttribute.getOrElse("").isEmpty) {
               updateAccount(x.copy(fullName = ldapUserInfo.fullName))
             } else {
               updateAccount(x.copy(mailAddress = ldapUserInfo.mailAddress, fullName = ldapUserInfo.fullName))
diff --git a/src/main/scala/service/SystemSettingsService.scala b/src/main/scala/service/SystemSettingsService.scala
index 7bc171b..df27bb7 100644
--- a/src/main/scala/service/SystemSettingsService.scala
+++ b/src/main/scala/service/SystemSettingsService.scala
@@ -41,8 +41,7 @@
           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.disableMailResolve.foreach(x => props.setProperty(LdapDisableMailResolve, x.toString))
+          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 +84,7 @@
             getValue(props, LdapUserNameAttribute, ""),
             getOptionValue(props, LdapAdditionalFilterCondition, None),
             getOptionValue(props, LdapFullNameAttribute, None),
-            getValue(props, LdapMailAddressAttribute, ""),
-            getOptionValue[Boolean](props, LdapDisableMailResolve, None),
+            getOptionValue(props, LdapMailAddressAttribute, None),
             getOptionValue[Boolean](props, LdapTls, None),
             getOptionValue(props, LdapKeystore, None)))
         } else {
@@ -119,8 +117,7 @@
     userNameAttribute: String,
     additionalFilterCondition: Option[String],
     fullNameAttribute: Option[String],
-    mailAttribute: String,
-    disableMailResolve: Option[Boolean],
+    mailAttribute: Option[String],
     tls: Option[Boolean],
     keystore: Option[String])
 
@@ -157,7 +154,6 @@
   private val LdapAdditionalFilterCondition = "ldap.additional_filter_condition"
   private val LdapFullNameAttribute = "ldap.fullname_attribute"
   private val LdapMailAddressAttribute = "ldap.mail_attribute"
-  private val LdapDisableMailResolve = "ldap.disable_mail_resolve"
   private val LdapTls = "ldap.tls"
   private val LdapKeystore = "ldap.keystore"
 
diff --git a/src/main/scala/util/LDAPUtil.scala b/src/main/scala/util/LDAPUtil.scala
index 9f23919..110b405 100644
--- a/src/main/scala/util/LDAPUtil.scala
+++ b/src/main/scala/util/LDAPUtil.scala
@@ -47,7 +47,7 @@
       keystore = ldapSettings.keystore.getOrElse(""),
       error    = "User LDAP Authentication Failed."
     ){ conn =>
-      if(ldapSettings.disableMailResolve.getOrElse(false)) {
+      if(ldapSettings.mailAttribute.getOrElse("").isEmpty) {
         Right(LDAPUserInfo(
           userName    = userName,
           fullName    = ldapSettings.fullNameAttribute.flatMap { fullNameAttribute =>
@@ -55,7 +55,7 @@
           }.getOrElse(userName),
           mailAddress = AccountUtil.getLdapDummyMailAddress(userName)))
       } else {
-        findMailAddress(conn, userDN, ldapSettings.mailAttribute) match {
+        findMailAddress(conn, userDN, ldapSettings.mailAttribute.get) match {
           case Some(mailAddress) => Right(LDAPUserInfo(
             userName    = userName,
             fullName    = ldapSettings.fullNameAttribute.flatMap { fullNameAttribute =>
diff --git a/src/main/twirl/admin/system.scala.html b/src/main/twirl/admin/system.scala.html
index dbd7daf..8e52c8d 100644
--- a/src/main/twirl/admin/system.scala.html
+++ b/src/main/twirl/admin/system.scala.html
@@ -133,13 +133,6 @@
             <div class="control-group">
               <div class="controls">
                 <label class="checkbox">
-                  <input type="checkbox" name="ldap.disableMailResolve"@if(settings.ldap.flatMap(_.disableMailResolve).getOrElse(false)){ checked}/> Disable mail resolve
-                </label>
-              </div>
-            </div>
-            <div class="control-group">
-              <div class="controls">
-                <label class="checkbox">
                   <input type="checkbox" name="ldap.tls"@if(settings.ldap.flatMap(_.tls).getOrElse(false)){ checked}/> Enable TLS
                 </label>
               </div>