diff --git a/src/main/scala/gitbucket/core/plugin/PluginRegistory.scala b/src/main/scala/gitbucket/core/plugin/PluginRegistory.scala
index c6dcc62..d31cb76 100644
--- a/src/main/scala/gitbucket/core/plugin/PluginRegistory.scala
+++ b/src/main/scala/gitbucket/core/plugin/PluginRegistory.scala
@@ -39,7 +39,11 @@
 
   private val repositoryHooks = new ListBuffer[RepositoryHook]
   private val issueHooks = new ListBuffer[IssueHook]
+  issueHooks += new gitbucket.core.util.Notifier.IssueHook()
+
   private val pullRequestHooks = new ListBuffer[PullRequestHook]
+  pullRequestHooks += new gitbucket.core.util.Notifier.PullRequestHook()
+
   private val globalMenus = new ListBuffer[(Context) => Option[Link]]
   private val repositoryMenus = new ListBuffer[(RepositoryInfo, Context) => Option[Link]]
   private val repositorySettingTabs = new ListBuffer[(RepositoryInfo, Context) => Option[Link]]
diff --git a/src/main/scala/gitbucket/core/util/Notifier.scala b/src/main/scala/gitbucket/core/util/Notifier.scala
index 0c7d861..3e8d39c 100644
--- a/src/main/scala/gitbucket/core/util/Notifier.scala
+++ b/src/main/scala/gitbucket/core/util/Notifier.scala
@@ -1,9 +1,10 @@
 package gitbucket.core.util
 
-import gitbucket.core.model.{Session, Account}
+import gitbucket.core.model.{Session, Issue, Account}
 import gitbucket.core.model.Profile.profile.blockingApi._
-import gitbucket.core.service.SystemSettingsService
+import gitbucket.core.service.{RepositoryService, AccountService, IssuesService, SystemSettingsService}
 import gitbucket.core.servlet.Database
+import gitbucket.core.view.Markdown
 
 import scala.concurrent._
 import scala.util.{Success, Failure}
@@ -30,6 +31,125 @@
     case settings if (settings.notification && settings.useSMTP) => new Mailer(settings.smtp.get)
     case _ => new MockMailer
   }
+
+
+  // TODO This class is temporary keeping the current feature until Notifications Plugin is available.
+  class IssueHook extends gitbucket.core.plugin.IssueHook
+    with RepositoryService with AccountService with IssuesService {
+
+    override def created(issue: Issue, r: RepositoryService.RepositoryInfo)(implicit context: Context): Unit = {
+      Notifier().toNotify(
+        subject(issue, r),
+        message(issue.content getOrElse "", r)(content => s"""
+          |$content<br/>
+          |--<br/>
+          |<a href="${s"${context.baseUrl}/${r.owner}/${r.name}/issues/${issue.issueId}"}">View it on GitBucket</a>
+          """.stripMargin)
+      )(recipients(issue))
+    }
+
+    override def addedComment(commentId: Int, content: String, issue: Issue, r: RepositoryService.RepositoryInfo)(implicit context: Context): Unit = {
+      Notifier().toNotify(
+        subject(issue, r),
+        message(content, r)(content => s"""
+          |$content<br/>
+          |--<br/>
+          |<a href="${s"${context.baseUrl}/${r.owner}/${r.name}/issues/${issue.issueId}#comment-$commentId"}">View it on GitBucket</a>
+          """.stripMargin)
+      )(recipients(issue))
+    }
+
+    override def closed(issue: Issue, r: RepositoryService.RepositoryInfo)(implicit context: Context): Unit = {
+      Notifier().toNotify(
+        subject(issue, r),
+        message("close", r)(content => s"""
+          |$content <a href="${s"${context.baseUrl}/${r.owner}/${r.name}/issues/${issue.issueId}"}">#${issue.issueId}</a>
+          """.stripMargin)
+      )(recipients(issue))
+    }
+
+    override def reopened(issue: Issue, r: RepositoryService.RepositoryInfo)(implicit context: Context): Unit = {
+      Notifier().toNotify(
+        subject(issue, r),
+        message("reopen", r)(content => s"""
+          |$content <a href="${s"${context.baseUrl}/${r.owner}/${r.name}/issues/${issue.issueId}"}">#${issue.issueId}</a>
+          """.stripMargin)
+      )(recipients(issue))
+    }
+
+
+    protected def subject(issue: Issue, r: RepositoryService.RepositoryInfo): String =
+      s"[${r.owner}/${r.name}] ${issue.title} (#${issue.issueId})"
+
+    protected def message(content: String, r: RepositoryService.RepositoryInfo)(msg: String => String)(implicit context: Context): String =
+      msg(Markdown.toHtml(
+        markdown         = content,
+        repository       = r,
+        enableWikiLink   = false,
+        enableRefsLink   = true,
+        enableAnchor     = false,
+        enableLineBreaks = false
+      ))
+
+    protected val recipients: Issue => Account => Session => Seq[String] = {
+      issue => loginAccount => implicit session =>
+        (
+          // individual repository's owner
+          issue.userName ::
+          // group members of group repository
+          getGroupMembers(issue.userName).map(_.userName) :::
+          // collaborators
+          getCollaboratorUserNames(issue.userName, issue.repositoryName) :::
+          // participants
+          issue.openedUserName ::
+          getComments(issue.userName, issue.repositoryName, issue.issueId).map(_.commentedUserName)
+        )
+        .distinct
+        .withFilter ( _ != loginAccount.userName )  // the operation in person is excluded
+        .flatMap (
+          getAccountByUserName(_)
+            .filterNot (_.isGroupAccount)
+            .filterNot (LDAPUtil.isDummyMailAddress)
+            .map (_.mailAddress)
+        )
+    }
+  }
+
+  // TODO This class is temporary keeping the current feature until Notifications Plugin is available.
+  class PullRequestHook extends IssueHook with gitbucket.core.plugin.PullRequestHook {
+    override def created(issue: Issue, r: RepositoryService.RepositoryInfo)(implicit context: Context): Unit = {
+      val url = s"${context.baseUrl}/${r.owner}/${r.name}/pull/${issue.issueId}"
+      Notifier().toNotify(
+        subject(issue, r),
+        message(issue.content getOrElse "", r)(content => s"""
+          |$content<hr/>
+          |View, comment on, or merge it at:<br/>
+          |<a href="$url">$url</a>
+          """.stripMargin)
+      )(recipients(issue))
+    }
+
+    override def addedComment(commentId: Int, content: String, issue: Issue, r: RepositoryService.RepositoryInfo)(implicit context: Context): Unit = {
+      Notifier().toNotify(
+        subject(issue, r),
+        message(content, r)(content => s"""
+          |$content<br/>
+          |--<br/>
+          |<a href="${s"${context.baseUrl}/${r.owner}/${r.name}/pull/${issue.issueId}#comment-$commentId"}">View it on GitBucket</a>
+          """.stripMargin)
+      )(recipients(issue))
+    }
+
+    override def merged(issue: Issue, r: RepositoryService.RepositoryInfo)(implicit context: Context): Unit = {
+      Notifier().toNotify(
+        subject(issue, r),
+        message("merge", r)(content => s"""
+          |$content <a href="${s"${context.baseUrl}/${r.owner}/${r.name}/pull/${issue.issueId}"}">#${issue.issueId}</a>
+          """.stripMargin)
+      )(recipients(issue))
+    }
+  }
+
 }
 
 class Mailer(private val smtp: Smtp) extends Notifier {