diff --git a/src/transport/smtp/async_transport.rs b/src/transport/smtp/async_transport.rs
index 24cc39d..8898f00 100644
--- a/src/transport/smtp/async_transport.rs
+++ b/src/transport/smtp/async_transport.rs
@@ -45,7 +45,7 @@ impl AsyncTransport for AsyncSmtpTransport<Tokio1Executor> {
         let result = conn.send(envelope, email).await?;
 
         #[cfg(not(feature = "pool"))]
-        conn.quit().await?;
+        conn.abort().await;
 
         Ok(result)
     }
diff --git a/src/transport/smtp/transport.rs b/src/transport/smtp/transport.rs
index 7244427..3bbc8b1 100644
--- a/src/transport/smtp/transport.rs
+++ b/src/transport/smtp/transport.rs
@@ -32,7 +32,7 @@ impl Transport for SmtpTransport {
         let result = conn.send(envelope, email)?;
 
         #[cfg(not(feature = "pool"))]
-        conn.quit()?;
+        conn.abort();
 
         Ok(result)
     }