Examples Not Working

[sezna]

I'm trying to use this crate in a project I'm working on, and I can't get the examples to compile. They cause panics.

My code (the example code):

use lettre::transport::smtp::{SmtpTransport, SmtpTransportBuilder};
use lettre::email::EmailBuilder;
use lettre::transport::EmailTransport;

let email = EmailBuilder::new()
                    .to("root@localhost")
                    .from("user@localhost")
                    .body("Hello World!")
                    .subject("Hello")
                    .build()
                    .unwrap();

// Open a local connection on port 25
let mut mailer =
SmtpTransportBuilder::localhost().unwrap().build();
// Send the email
let result = mailer.send(email);

assert!(result.is_ok());

The error:

thread '<main>' panicked at 'assertion failed: result.is_ok()', main.rs:26
note: Run with `RUST_BACKTRACE=1` for a backtrace.
Process didn't exit successfully: `/path/to/code` (exit code: 101)

[sezna]

I can't seem to edit my post on my mobile browser but I made a typo. It is a runtime error, not a compile error.

[amousset]

You should try to print the content of result, it will give you the reason of the failure.

[sezna]

Ok, I did that, and this is what it gave me:

an I/O error occurred

It may be something I'm doing incorrectly, and if so, sorry about that, but I can't seem to locate an error on my end. I'm not doing any I/O.

[amousset]

You can try to display the error cause with error.cause(), it should give more details about the I/O error.

[amousset]

You can also have a look at the logs of your local mail server to see where the failure happens.

[djc]

I actually have similar problems. In my case, I get "an I/O error occurred", and the underlying failure is "connection refused". I'm using the same SmtpTransportBuilder as the reporter, and I verified with a Python script that using SMTP through localhost:25 is working fine there.

[djc]

BTW, I can reproduce this with cargo test against current master or v0.5.1:

test transport_smtp::simple_sender ... FAILED

failures:

---- transport_smtp::simple_sender stdout ----
    thread 'transport_smtp::simple_sender' panicked at 'assertion failed: result.is_ok()', tests/transport_smtp.rs:18
stack backtrace:
   1:     0x5649b8e4cd50 - std::sys::backtrace::tracing::imp::write::h82353b94d9957b5a
   2:     0x5649b8e5092b - std::panicking::default_hook::_$u7b$$u7b$closure$u7d$$u7d$::hd08c9fd28a21a931
   3:     0x5649b8e5051c - std::panicking::default_hook::h9f5ce461fe95b992
   4:     0x5649b8e416b8 - std::panicking::rust_panic_with_hook::hfb9137c9fa89bbb0
   5:     0x5649b8d7c777 - std::panicking::begin_panic::h91a119e8e2811f21
                        at src/libstd/panicking.rs:328
   6:     0x5649b8d7a38b - lib::transport_smtp::simple_sender::hd483d90c8b7a0dbd
                        at /home/djc/src/lettre/<std macros>:3
   7:     0x5649b8db8c36 - _<F as std..boxed..FnBox<A>>::call_box::h8c9c9860460d767a
   8:     0x5649b8dbb367 - std::panicking::try::call::h5112e6c4747ac9f2
   9:     0x5649b8e5a12b - __rust_try
  10:     0x5649b8e5a0ce - __rust_maybe_catch_panic
  11:     0x5649b8dbb78e - _<F as std..boxed..FnBox<A>>::call_box::h7b2b6b6ac924dcb2
  12:     0x5649b8e4ef44 - std::sys::thread::Thread::new::thread_start::h99197ac7442ad7fa
  13:     0x7f9013b14493 - start_thread
  14:     0x7f90136425dc - __clone
  15:                0x0 - <unknown>


failures:
    transport_smtp::simple_sender

test result: FAILED. 2 passed; 1 failed; 0 ignored; 0 measured

error: test failed

[amousset]

Can you run your test with the latest version (I just added a new log) from master with RUST_LOG=debug ./program to get full logs?

Which mail server is running on this host? Could you try to connect with telnet on port 25 (telnet localhost 25), type EHLO localhost and give the result?

[djc]

Aha! Here's the output from running sezna's test program against git master lettre:

djc@enrai rusttest $ RUST_LOG=debug ./target/debug/rusttest 
DEBUG:lettre::transport::smtp::client: connecting to [::1]:25
thread '<main>' panicked at 'assertion failed: result.is_ok()', src/main.rs:25
note: Run with `RUST_BACKTRACE=1` for a backtrace.

For some reason, Rust/lettre is resolving localhost to ::1. However, my Postfix (3.0.3) instance is only listening on IPv4. When I try gethostbyname('localhost') from Python, I get IPv4:

>>> import socket
>>> print socket.gethostbyname('localhost')
127.0.0.1
>>> sock = socket.socket()
>>> sock.connect(('localhost', 25))
>>> sock.send('EHLO localhost\n')
15
>>> print sock.recv(1024)
220 enrai.xavamedia.nl ESMTP Postfix
250-enrai.xavamedia.nl
250-PIPELINING
250-SIZE 26214400
250-VRFY
250-ETRN
250-STARTTLS
250-ENHANCEDSTATUSCODES
250-8BITMIME
250-DSN
250 SMTPUTF8

>>>

[amousset]

Then you can use SmtpTransportBuilder::new("127.0.0.1:25") to connect to ipv4.

[djc]

Sure, but why doesn't Rust/lettre resolve localhost the same as Python (as well as just ping)?

[amousset]

I don't know, closing as it is not really related to lettre.