diff --git a/lettre/src/stub/mod.rs b/lettre/src/stub/mod.rs
index a33f2d3..d0f385b 100644
--- a/lettre/src/stub/mod.rs
+++ b/lettre/src/stub/mod.rs
@@ -25,33 +25,30 @@
 
 use EmailTransport;
 use SendableEmail;
-use smtp::error::{Error, SmtpResult};
-use smtp::response::{Code, Response};
 use std::io::Read;
-use std::str::FromStr;
 
 /// This transport logs the message envelope and returns the given response
 #[derive(Debug)]
 pub struct StubEmailTransport {
-    response: Response,
+    response: StubResult,
 }
 
 impl StubEmailTransport {
     /// Creates a new transport that always returns the given response
-    pub fn new(response: Response) -> StubEmailTransport {
+    pub fn new(response: StubResult) -> StubEmailTransport {
         StubEmailTransport { response: response }
     }
 
     /// Creates a new transport that always returns a success response
     pub fn new_positive() -> StubEmailTransport {
         StubEmailTransport {
-            response: Response::new(Code::from_str("200").unwrap(), vec!["ok".to_string()]),
+            response: Ok(()),
         }
     }
 }
 
 /// SMTP result type
-pub type StubResult = SmtpResult;
+pub type StubResult = Result<(), ()>;
 
 impl<'a, T: Read + 'a> EmailTransport<'a, T, StubResult> for StubEmailTransport {
     fn send<U: SendableEmail<'a, T>>(&mut self, email: &'a U) -> StubResult {
@@ -62,10 +59,6 @@ impl<'a, T: Read + 'a> EmailTransport<'a, T, StubResult> for StubEmailTransport
             email.from(),
             email.to()
         );
-        if self.response.is_positive() {
-            Ok(self.response.clone())
-        } else {
-            Err(Error::from(self.response.clone()))
-        }
+        self.response
     }
 }
diff --git a/lettre/tests/transport_stub.rs b/lettre/tests/transport_stub.rs
index e8fac19..23976cf 100644
--- a/lettre/tests/transport_stub.rs
+++ b/lettre/tests/transport_stub.rs
@@ -1,16 +1,12 @@
 extern crate lettre;
 
 use lettre::{EmailAddress, EmailTransport, SimpleSendableEmail};
-use lettre::smtp::response::{Code, Response};
 use lettre::stub::StubEmailTransport;
-use std::str::FromStr;
 
 #[test]
 fn stub_transport() {
     let mut sender_ok = StubEmailTransport::new_positive();
-    let response_ok = Response::new(Code::from_str("200").unwrap(), vec!["ok".to_string()]);
-    let response_ko = Response::new(Code::from_str("510").unwrap(), vec!["ko".to_string()]);
-    let mut sender_ko = StubEmailTransport::new(response_ko);
+    let mut sender_ko = StubEmailTransport::new(Err(()));
 
     let email = SimpleSendableEmail::new(
         EmailAddress::new("user@localhost".to_string()),
@@ -19,10 +15,6 @@ fn stub_transport() {
         "Hello stub".to_string(),
     );
 
-    let result_ok = sender_ok.send(&email).unwrap();
-    let result_ko = sender_ko.send(&email);
-
-    assert_eq!(result_ok, response_ok);
-    assert!(result_ko.is_err());
-
+    sender_ok.send(&email).unwrap();
+    sender_ko.send(&email).unwrap_err();
 }