diff --git a/cx-auto-sign/Notification.cs b/cx-auto-sign/Notification.cs
index 1b6da4e..6fb00c9 100644
--- a/cx-auto-sign/Notification.cs
+++ b/cx-auto-sign/Notification.cs
@@ -1,5 +1,4 @@
 using System;
-using System.Net;
 using System.Text;
 using CxSignHelper;
 using MailKit.Net.Smtp;
diff --git a/cx-auto-sign/cx-auto-sign.csproj b/cx-auto-sign/cx-auto-sign.csproj
index e4ebf05..dfb8163 100644
--- a/cx-auto-sign/cx-auto-sign.csproj
+++ b/cx-auto-sign/cx-auto-sign.csproj
@@ -5,7 +5,7 @@
     <TargetFramework>net5.0</TargetFramework>
     <RootNamespace>cx_auto_sign</RootNamespace>
     <PackageProjectUrl>https://github.com/cyanray/cx-auto-sign</PackageProjectUrl>
-    <Version>2.1.5</Version>
+    <Version>2.1.6</Version>
   </PropertyGroup>
 
   <ItemGroup>
diff --git a/ver.sh b/ver.sh
index 056e6b5..efe815d 100644
--- a/ver.sh
+++ b/ver.sh
@@ -1,4 +1,4 @@
-ver=2.1.5
+ver=2.1.6
 ver_file=./cx-auto-sign/cx-auto-sign.csproj
 
 function set-ver() {