diff --git a/db/db-core/src/lib.rs b/db/db-core/src/lib.rs
index e299b743..f8304999 100644
--- a/db/db-core/src/lib.rs
+++ b/db/db-core/src/lib.rs
@@ -86,6 +86,9 @@ pub trait MCDatabase: std::marker::Send + std::marker::Sync + CloneSPDatabase {
 
     /// check if username exists
     async fn username_exists(&self, username: &str) -> DBResult<bool>;
+
+    /// check if email exists
+    async fn email_exists(&self, email: &str) -> DBResult<bool>;
 }
 
 /// Trait to clone MCDatabase
diff --git a/db/db-core/src/tests.rs b/db/db-core/src/tests.rs
index e6c3eda3..cdc9f04d 100644
--- a/db/db-core/src/tests.rs
+++ b/db/db-core/src/tests.rs
@@ -28,6 +28,10 @@ pub async fn database_works<'a, T: MCDatabase>(db: &T, p: &Register<'a>) {
         );
     }
     db.register(p).await.unwrap();
+    assert!(
+        db.email_exists(p.email.as_ref().unwrap()).await.unwrap(),
+        "user is registered so email should exsit"
+    );
     assert!(
         db.username_exists(p.username).await.unwrap(),
         "user is registered so username should exsit"
@@ -46,4 +50,9 @@ pub async fn database_works<'a, T: MCDatabase>(db: &T, p: &Register<'a>) {
         db.username_exists(p2.username).await.unwrap(),
         "user is registered so username should exsit"
     );
+    assert!(
+        !db.email_exists(p.email.as_ref().unwrap()).await.unwrap(),
+        "user registration with email is deleted; so email shouldn't exsit"
+    );
+
 }