Show admins the email server error message when email sending fails (#2073)

* Show admins the email server error message when email sending fails

CTFd/api/v1/users.py

@@ -477,4 +477,10 @@ class UserEmails(Resource):
 
         result, response = sendmail(addr=user.email, text=text)
 
-        return {"success": result}
+        if result is True:
+            return {"success": True}
+        else:
+            return (
+                {"success": False, "errors": {"": [response]}},
+                400,
+            )

tests/api/v1/test_users.py

@@ -894,7 +894,9 @@ def test_api_user_send_email():
             r = admin.post(
                 "/api/v1/users/2/email", json={"text": "email should be accepted"}
             )
-            assert r.status_code == 200
+            # Email should go through but since we aren't mocking
+            # the server we get a Connection refused error
+            assert r.status_code == 400
 
     destroy_ctfd(app)