I want to send a message containing an email in a template, but I don't want to call SmtpClient Builder::new every time for each email.
Maybe you know how to make it more elastic?

let template = format!("Dear {email}, You are now change your email.");
let emails = vec![...];
let message = MessageBuilder::new()
            .from((username, email))
            .to(emails)
            .subject("Subject")
            .text_body(&template);
 
 SmtpClientBuilder::new(self.hostname.clone(), self.port)
            .implicit_tls(false)
            .credentials((self.from.clone(), self.password.clone()))
            .connect()
            .await
            .expect("connect to send email")
            .send(message)
            .await
            .unwrap();

As a solution maybe need implement .send_many(message) where we can create message for every individual user?

Hello!

I've been using thiserror and stumbled upon this when trying to integrate mail_send:

mail_send::Error (and also mail_auth::Error) do not implement the std::error::Error trait. That's why they cannot be simply integrated into other error-frameworks which all build on the std lib's Error trait.

mail_send and mail_auth could also opt into using the thiserror crate.
thiserror::Error is entirely transparent to the library user, and takes some boilerplate away from you.

Here's how this could look like: https://github.com/jolimail/mrml-core/pull/38/files#diff-c08afca406e15cd665ef6c443014a8472bb79435231a21463239333886aed304

A pure std::error::Error implementation, without #[derive(thiserror::Error)] might look like this: https://docs.rs/askama_shared/0.12.2/src/askama_shared/error.rs.html#43-54

Is there a way to totally disable SSL/TLS? I am replacing lettre by mail-send, and I don't see how to do it. The equivalent with lettre is:

SmtpTransport::relay(&config.host)?.tls(Tls::None);

mail-send::Error can't enum by thiserror crate.

Adding this crate to even cargo's default hello world program causes it to fail to compile:

error[E0599]: &HeaderType<'_> is not an iterator
--> /home/westly/.cargo/registry/src/github.com-1ecc6299db9ec823/mail-send-0.2.0/src/smtp/message.rs:160:91
|
160 | if let Some(HeaderType::Address(address::Address::Address(addr))) = value.last() {
| ^^^^ &HeaderType<'_> is not an iterator
|
::: /home/westly/.cargo/registry/src/github.com-1ecc6299db9ec823/mail-builder-0.2.1/src/headers/mod.rs:32:1
|
32 | pub enum HeaderType<'x> {
| ----------------------- doesn't satisfy HeaderType<'_>: Iterator
|
= note: the following trait bounds were not satisfied:
&HeaderType<'_>: Iterator
which is required by &mut &HeaderType<'_>: Iterator
HeaderType<'_>: Iterator
which is required by &mut HeaderType<'_>: Iterator

error[E0277]: &HeaderType<'_> is not an iterator
--> /home/westly/.cargo/registry/src/github.com-1ecc6299db9ec823/mail-send-0.2.0/src/smtp/message.rs:170:29
|
170 | for addr in value {
| ^^^^^ &HeaderType<'_> is not an iterator
|
= help: the trait Iterator is not implemented for &HeaderType<'_>
= note: required because of the requirements on the impl of IntoIterator for &HeaderType<'_>

Some errors have detailed explanations: E0277, E0599.
For more information about an error, try rustc --explain E0277.
error: could not compile mail-send due to 2 previous errors
warning: build failed, waiting for other jobs to finish...

Trying to move away from lettre in favor of an actively maintained crate. I immediately noticed that there's no documentation for the API and there's a lot of implementations missing that one would expect to be present such as impl From<EmailAddress> for Address.
Great job so far though, wish I had the time to offer a helping hand.

Introduction

Hi! I love this project idea and really appreciate the dedication to modern security standards (such as DKIM support) as well as mail-send's RFC compliance. The current feature set would serve as a fantastic base for a security-oriented Rust-written mail client if that is something Stalwart Labs would be interested in pursuing.

The final component of mail-send that would make it a serious security contender (in terms of client features) to the likes of ProtonMail and Tutanota would be support for OpenPGP, the open standard for email encryption.

Proposal

Standards

mail-send could implement OpenPGP support by following these Internet Message Format standards:

• RFC 4880 OpenPGP Message Format
• RFC 3156 MIME* Security with OpenPGP

There are two strong libraries that have implemented RFC 4880: rpgp and sequoia.

*Comparison of OpenPGP vs. PGP/MIME and a table of major email client support for them

Implementation

The loading of a public PGP key could be done in a similar syntax to the implementation of DKIM in this crate:

// Set up DKIM signer
let pgp_key = PGP::from_pkcs1_asc_file("./key.asc")
    .unwrap()

^ I'm not very familiar with PGP so not sure if any other inputs besides the file path should be provided

// Build a encrypted text message with a single attachment
let message = MessageBuilder::new()
    .from(("John Doe", "[email protected]"))
    .to("[email protected]")
    .subject("Howdy!")
    .text_body("These pretzels are making me thirsty.")
    .binary_attachment("image/png", "pretzels.png", [1, 2, 3, 4].as_ref())
    .pgp_encrypt(pgp_key);

Interested to hear your thoughts! Let me know if this issue would be better suited at mail-builder.

It'd be useful if SmtpClient.send() returned the reported queue ID for that particular email, to help diagnose delivery problems by identifying a particular send of an email.

DATA
354 End data with <CR><LF>.<CR><LF>
email body here
.
250 2.0.0 Ok: queued as 224B824BD40

Hi, it's me again

What I'm trying to build requires to store mails on disk, before reading them back and sending them.

Storing them on disk using mail-parser is easy thanks to serde. An alternative could be to store them raw which is trivial too.

However, sending them through mail-send seems to be a bit of a pain point. Indeed, the IntoMessage trait that Transport.send expects is implemented for mail-parser's Message and mail-builder MessageBuilder.

However, neither mail-parser::Message nor mail-builder::MessageBuilder support building the structure from the raw text or through Deserialize.

I guess implementing IntoMessage for mail-parser::Message could work, but it feels like both mail-parser::Message and mail-send::smtp::message::Message could be the same structure, that would implement Serialize/Deserialize?

Thanks!

Hi!

I am experiencing some weird SMTP failures.

I have a mailhog (https://github.com/mailhog/MailHog / https://registry.hub.docker.com/r/mailhog/mailhog/) set up behind a traefik (https://registry.hub.docker.com/_/traefik) reverse proxy. The entire thing is happening within a docker environment on my local machine - no remote network failures.

The setup is simple: MailHog just exposes port 1025 for plain SMTP; Traefik does the TLS and exposes port 587. (TLS is self-signed; using allow_invalid_certs().)

The Traefik config for the TLS & TCP setup is basically the same as the one shown here: https://docker-mailserver.github.io/docker-mailserver/edge/examples/tutorials/mailserver-behind-proxy/#configuration-of-the-used-proxy-software

Most of the time, I can send mail just fine.
However, every now and then I receive an UnparseableReply error.

I can reproduce it by just running the test again and again. It does not matter if I run it in quick succession or wait for a second or more before retrying.

In these cases, mailhog logs:

Starting session
[PROTO: INVALID] Started session, switching to ESTABLISH state
Sent 45 bytes: '220 mail.some-host.berlin ESMTP MailHog\r\n'
Received 15 bytes: 'EHLO felicity\r\n'
[PROTO: ESTABLISH] Processing line: EHLO felicity
[PROTO: ESTABLISH] In state 1, got command 'EHLO', args 'felicity'
[PROTO: ESTABLISH] In ESTABLISH state
[PROTO: ESTABLISH] Got EHLO command, switching to MAIL state
Sent 20 bytes: '250-Hello felicity\r\n'
Sent 16 bytes: '250-PIPELINING\r\n'
Sent 16 bytes: '250 AUTH PLAIN\r\n'
Connection closed by remote host
Session ended

Note: Connection closed by remote host (by mail-send.)

The SmtpClientBuilder's timeout is set to 30 seconds. The test sending, however, fails immediately.

Note that this test is done without Credentials.

Where Connection closed by remote host occurs, commonly MailHog should receive the first header: Received 30 bytes: 'MAIL FROM:<[email protected]>\r\n'. See below for a full (elided message body) example of a successful send.

And my test shows:

running 2 tests
test tests::renders_full_newsletter ... ok
test mail::tests::mailer_sends_smtp_tls_mail ... FAILED

failures:

---- mail::tests::mailer_sends_smtp_tls_mail stdout ----
Error: SendMail(UnparseableReply)


failures:
    mail::tests::mailer_sends_smtp_tls_mail

test result: FAILED. 1 passed; 1 failed; 0 ignored; 0 measured; 0 filtered out; finished in 0.01s

error: test failed, to rerun pass `--lib`

SendMail is my own error enum variant. UnparseableReply is mail_send::Error.

Traefik writes nothing special to the log (log level Debug):

Handling connection from 172.254.1.1:48226

In contrast, here's the MailHog logs from a good mail send:

Starting session
[PROTO: INVALID] Started session, switching to ESTABLISH state
Sent 45 bytes: '220 mail.some-host.berlin ESMTP MailHog\r\n'
Received 15 bytes: 'EHLO felicity\r\n'
[PROTO: ESTABLISH] Processing line: EHLO felicity
[PROTO: ESTABLISH] In state 1, got command 'EHLO', args 'felicity'
[PROTO: ESTABLISH] In ESTABLISH state
[PROTO: ESTABLISH] Got EHLO command, switching to MAIL state
Sent 20 bytes: '250-Hello felicity\r\n'
Sent 16 bytes: '250-PIPELINING\r\n'
Sent 16 bytes: '250 AUTH PLAIN\r\n'
Received 30 bytes: 'MAIL FROM:<[email protected]>\r\n'
[PROTO: MAIL] Processing line: MAIL FROM:<[email protected]>
[PROTO: MAIL] In state 6, got command 'MAIL', args 'FROM:<[email protected]>'
[PROTO: MAIL] In MAIL state
[PROTO: MAIL] Got MAIL command, switching to RCPT state
Sent 32 bytes: '250 Sender [email protected] ok\r\n'
Received 26 bytes: 'RCPT TO:<[email protected]>\r\n'
[PROTO: RCPT] Processing line: RCPT TO:<[email protected]>
[PROTO: RCPT] In state 7, got command 'RCPT', args 'TO:<[email protected]>'
[PROTO: RCPT] In RCPT state
[PROTO: RCPT] Got RCPT command
Sent 33 bytes: '250 Recipient [email protected] ok\r\n'
Received 6 bytes: 'DATA\r\n'
[PROTO: RCPT] Processing line: DATA
[PROTO: RCPT] In state 7, got command 'DATA', args ''
[PROTO: RCPT] In RCPT state
[PROTO: RCPT] Got DATA command, switching to DATA state
Sent 37 bytes: '354 End data with <CR><LF>.<CR><LF>\r\n'
Received 1024 bytes: 'From: <[email protected]>\r\nTo: <[email protected]>\r\nSubject: Test mail\r\nReply-To: <[email protected]>\r\nMessage-ID: <174421ede9d619d9.fbb0693af3efc5c7.146ed3f42bb856b@felicity>\r\nDate: Wed, 15 Feb 2023 23:04:27 +0000\r\nContent-Type: text/html; charset="utf-8"\r\nContent-Transfer-Encoding: quoted-printable\r\n\r\n<!doctype html><html xmlns=3D"http://www.w3.org/1999/xhtml" xmlns:v=3D"urn:s=\r\nchemas-microsoft-com:vml" xmlns:o=3D"urn:schemas-microsoft-com:office:office=\r\n"> [... AND SO ON, receiving the entire mail in chunks of up to 1024 B]'
[PROTO: DATA] Got EOF, storing message and switching to MAIL state
Parsing Content from string: 'From: <[email protected]>
To: <[email protected]>
Subject: Test mail
Reply-To: <[email protected]>
Message-ID: <174421ede9d619d9.fbb0693af3efc5c7.146ed3f42bb856b@felicity>
Date: Wed, 15 Feb 2023 23:04:27 +0000
Content-Type: text/html; charset="utf-8"
Content-Transfer-Encoding: quoted-printable

<!doctype html><html xmlns=3D"http://www.w3.org/1999/xhtml" xmlns:v=3D"urn:s=
chemas-microsoft-com:vml" xmlns:o=3D"urn:schemas-microsoft-com:office:office=
">[AND SO ON... rest of the mail - not relevant to the bug report]'
Storing message ZjsPQpZCLXvLR44_7SWRBJpCTy9AfPV4JL_CvweyeoU=@mail.some-host.berlin
Sent 90 bytes: '250 Ok: queued as ZjsPQpZCLXvLR44_7SWRBJpCTy9AfPV4JL_CvweyeoU=@mail.some-host.berlin\r\n'
Got message in APIv2 websocket channel
[APIv2] BROADCAST /api/v2/websocket
Got message in APIv1 event stream
Connection closed by remote host
Session ended

PS: "Jim, the Chaos Monkey" (a MailHog feature intended to test application resilience in the face of failure) is disabled.

Hello

Do you have a sample in your code that will successfully email using SMPT XOAUTH2?

Url and scopes used to get token.

    AuthUrl::new("https://accounts.google.com/o/oauth2/v2/auth".to_string())?,
    TokenUrl::new("https://oauth2.googleapis.com/token".to_string())?,

    Scope::new("https://www.googleapis.com/auth/gmail.send".to_string()),
    Scope::new("email".to_string()),
    Scope::new("profile".to_string()),

This is the sample code I created

let auth_code_grant = AuthCodeGrant::new(
    ClientId::new(client_id.to_string()),
    client_secret,
let message = MessageBuilder::new()
    .from((sender_name.as_ref(), sender_email.as_ref()))
    .to(vec![(receiver_name.as_ref(), receiver_email.as_ref())])
    .subject("Microsoft - Test XOAUTH2 SMTP!")
    .html_body("<h1>Hello, world!</h1>")
    .text_body("Hello world!");

let credentials =
    Credentials::new_xoauth2(sender_email.as_ref(), access_token.secret().as_str());
log::info!("Authenticating SMTP XOAUTH2 Credentials....");
let email_connect = SmtpClientBuilder::new("smtp.gmail.com", 587)
    .implicit_tls(false)
    .credentials(credentials)
    .connect()
    .await;

match email_connect {
    Ok(mut result) => {
        log::info!("Sending SMTP XOAUTH2 Email....");
        let send = result.send(message).await;
        match send {
            Ok(_result) => {}
            Err(err) => {
                log::error!("SMTP Sending Error: {err:?}");
            }
        }
    }
    Err(err) => {
        log::error!("SMTP Connecting Error: {err:?}");
    }
}

But I got this error.
AuthenticationFailed(Response { code: 535, esc: [5, 7, 8], message: "Username and Password not accepted. Learn more at\n https://support.google.com/mail/?p=BadCredentials p5-20020a1709028a8500b001ab0d815dbbsm2483183plo.23 - gsmtp" })

I there any lacking in building the email?

version: mail-send = "0.3.0"

when not connect to stmp with tls:
match SmtpClientBuilder::new(email_host,25) .implicit_tls(false) .credentials((email_username, email_password)) .timeout(Duration::from_secs(3)) .connect() .await .unwrap() .send(message) .await { Ok(_) => println!("Email sent successfully!"), Err(e) => panic!("Could not send email: {:?}", e), }

thread 'main' panicked at 'called Result::unwrap() on an Err value: MissingStartTls',

Mail-send is licensed under mit/apache, while it's dependency smtp-proto - under AGPL3.0.

AGPL requires all derived work to be licensed under AGPL. Thus mail_send must be AGPL3.0 too.

Violation of the license of its dependency, makes the mail_send crate unusable.

Adding a binary attachment makes the sent command get stuck and never finish until the server ends the connection. Sending a text attachment works fine. The binary attachment is only 98Kb.

I need the exact conversion method as defined here:

Hi,

Thanks for publishing this crate and all the other, related, ones.

I'd like to use it in a small program that wouldn't use async or tokio, and it's not clear to me whether it can be done.

The doc says:

Full async (requires Tokio).

which is a bit ambiguous to me. Does it support async with a dependency on tokio if it is enabled, or is the crate only designed to support async?

If the latter, do you have any plans on supporting non-async?