diff --git a/.sqlx/query-7c8b84da6d70cb4ae59ae618e6f7aa7bde3dbd6630bd7e7fcafe1606d63651c8.json b/.sqlx/query-7c8b84da6d70cb4ae59ae618e6f7aa7bde3dbd6630bd7e7fcafe1606d63651c8.json
new file mode 100644
index 00000000..f775bb11
--- /dev/null
+++ b/.sqlx/query-7c8b84da6d70cb4ae59ae618e6f7aa7bde3dbd6630bd7e7fcafe1606d63651c8.json
@@ -0,0 +1,23 @@
+{
+  "db_name": "PostgreSQL",
+  "query": "\n      SELECT EXISTS(\n        SELECT 1\n        FROM af_workspace_invitation\n        WHERE id = $1 AND invitee_email = (SELECT email FROM af_user WHERE uuid = $2)\n      )\n    ",
+  "describe": {
+    "columns": [
+      {
+        "ordinal": 0,
+        "name": "exists",
+        "type_info": "Bool"
+      }
+    ],
+    "parameters": {
+      "Left": [
+        "Uuid",
+        "Uuid"
+      ]
+    },
+    "nullable": [
+      null
+    ]
+  },
+  "hash": "7c8b84da6d70cb4ae59ae618e6f7aa7bde3dbd6630bd7e7fcafe1606d63651c8"
+}
diff --git a/src/mailer.rs b/src/mailer.rs
index c3976e58..8d4a797b 100644
--- a/src/mailer.rs
+++ b/src/mailer.rs
@@ -36,9 +36,9 @@ impl Mailer {
 
     HANDLEBARS
       .write()
-      .unwrap()
+      .map_err(|err| anyhow::anyhow!(format!("Failed to write handlebars: {}", err)))?
       .register_template_string("workspace_invite", workspace_invite_template)
-      .unwrap();
+      .map_err(|err| anyhow::anyhow!(format!("Failed to register handlebars template: {}", err)))?;
 
     Ok(Self {
       smtp_transport,
@@ -51,10 +51,10 @@ impl Mailer {
     email: String,
     param: WorkspaceInviteMailerParam,
   ) -> Result<(), anyhow::Error> {
-    let rendered = HANDLEBARS
-      .read()
-      .unwrap()
-      .render("workspace_invite", &param)?;
+    let rendered = match HANDLEBARS.read() {
+      Ok(registory) => registory.render("workspace_invite", &param)?,
+      Err(err) => anyhow::bail!(format!("Failed to render handlebars template: {}", err)),
+    };
 
     let email = Message::builder()
       .from(lettre::message::Mailbox::new(
@@ -63,7 +63,7 @@ impl Mailer {
       ))
       .to(lettre::message::Mailbox::new(
         Some(param.username.clone()),
-        email.parse().unwrap(),
+        email.parse()?,
       ))
       .subject(format!(
         "Action required: {} invited you to {} in AppFlowy",