extern crate lettre; use lettre::transport::stub::StubEmailTransport; use lettre::transport::EmailTransport; use lettre::email::EmailBuilder; #[test] fn stub_transport() { let mut sender = StubEmailTransport; let email = EmailBuilder::new() .to("root@localhost") .from("user@localhost") .body("Hello World!") .subject("Hello") .build() .unwrap(); let result = sender.send(email); assert!(result.is_ok()); }