Updated lettre (and other crates) and workflow.

General:
- Updated several dependancies

Lettre:
- Updateded lettere and the workflow
- Changed encoding to base64
- Convert unix newlines to dos newlines for e-mails.
- Created custom e-mail boundary (auto generated could cause errors)

Tested the e-mails sent using several clients (Linux, Windows, MacOS, Web).
Run msglint (https://tools.ietf.org/tools/msglint/) on the generated e-mails until all errors were gone.

Lettre has changed quite some stuff compared between alpha.1 and alpha.2, i haven't noticed any issues sending e-mails during my tests.

src/error.rs

@@ -49,7 +49,7 @@ use yubico::yubicoerror::YubicoError as YubiErr;
 use lettre::address::AddressError as AddrErr;
 use lettre::error::Error as LettreErr;
 use lettre::message::mime::FromStrError as FromStrErr;
-use lettre::transport::smtp::error::Error as SmtpErr;
+use lettre::transport::smtp::Error as SmtpErr;
 
 #[derive(Serialize)]
 pub struct Empty {}

src/mail.rs

@@ -2,14 +2,13 @@ use std::{env, str::FromStr};
 
 use chrono::{DateTime, Local};
 use chrono_tz::Tz;
-use native_tls::{Protocol, TlsConnector};
 use percent_encoding::{percent_encode, NON_ALPHANUMERIC};
 
 use lettre::{
     message::{header, Mailbox, Message, MultiPart, SinglePart},
     transport::smtp::authentication::{Credentials, Mechanism as SmtpAuthMechanism},
     transport::smtp::extension::ClientId,
-    Address, SmtpTransport, Tls, TlsParameters, Transport,
+    Address, SmtpTransport, Transport,
 };
 
 use crate::{
@@ -20,28 +19,23 @@ use crate::{
 };
 
 fn mailer() -> SmtpTransport {
+    use std::time::Duration;
     let host = CONFIG.smtp_host().unwrap();
 
-    let client_security = if CONFIG.smtp_ssl() {
-        let tls = TlsConnector::builder()
-            .min_protocol_version(Some(Protocol::Tlsv11))
-            .build()
-            .unwrap();
-
-        let params = TlsParameters::new(host.clone(), tls);
-
+    // Determine security
+    let smtp_client = if CONFIG.smtp_ssl() {
         if CONFIG.smtp_explicit_tls() {
-            Tls::Wrapper(params)
+            SmtpTransport::relay(host.as_str())
         } else {
-            Tls::Required(params)
+            SmtpTransport::starttls_relay(host.as_str())
         }
     } else {
-        Tls::None
+        Ok(SmtpTransport::builder_dangerous(host.as_str()))
     };
 
-    use std::time::Duration;
-
-    let smtp_client = SmtpTransport::builder(host).port(CONFIG.smtp_port()).tls(client_security);
+    let smtp_client = smtp_client.unwrap()
+        .port(CONFIG.smtp_port())
+        .timeout(Some(Duration::from_secs(CONFIG.smtp_timeout())));
 
     let smtp_client = match (CONFIG.smtp_username(), CONFIG.smtp_password()) {
         (Some(user), Some(pass)) => smtp_client.credentials(Credentials::new(user, pass)),
@@ -49,7 +43,7 @@ fn mailer() -> SmtpTransport {
     };
 
     let smtp_client = match CONFIG.helo_name() {
-        Some(helo_name) => smtp_client.hello_name(ClientId::new(helo_name)),
+        Some(helo_name) => smtp_client.hello_name(ClientId::Domain(helo_name)),
         None => smtp_client,
     };
 
@@ -66,7 +60,7 @@ fn mailer() -> SmtpTransport {
         _ => smtp_client,
     };
 
-    smtp_client.timeout(Some(Duration::from_secs(CONFIG.smtp_timeout()))).build()
+    smtp_client.build()
 }
 
 fn get_text(template_name: &'static str, data: serde_json::Value) -> Result<(String, String, String), Error> {
@@ -84,8 +78,9 @@ fn get_template(template_name: &str, data: &serde_json::Value) -> Result<(String
         None => err!("Template doesn't contain subject"),
     };
 
+    use newline_converter::unix2dos;
     let body = match text_split.next() {
-        Some(s) => s.trim().to_string(),
+        Some(s) => unix2dos(s.trim()).to_string(),
         None => err!("Template doesn't contain body"),
     };
 
@@ -303,25 +298,18 @@ fn send_email(address: &str, subject: &str, body_html: &str, body_text: &str) ->
 
     let address = format!("{}@{}", address_split[1], domain_puny);
 
-    let data = MultiPart::mixed()
-        .multipart(
-            MultiPart::alternative()
-                .singlepart(
-                    SinglePart::quoted_printable()
-                        .header(header::ContentType("text/plain; charset=utf-8".parse()?))
-                        .body(body_text),
-                )
-                .multipart(
-                    MultiPart::related().singlepart(
-                        SinglePart::quoted_printable()
-                            .header(header::ContentType("text/html; charset=utf-8".parse()?))
-                            .body(body_html),
-                    )
-                    // .singlepart(SinglePart::base64() -- Inline files would go here
-                ),
-        )
-        // .singlepart(SinglePart::base64()  -- Attachments would go here
-        ;
+    let html = SinglePart::base64()
+        .header(header::ContentType("text/html; charset=utf-8".parse()?))
+        .body(body_html);
+
+    let text = SinglePart::base64()
+        .header(header::ContentType("text/plain; charset=utf-8".parse()?))
+        .body(body_text);
+
+    // The boundary generated by Lettre it self is mostly too large based on the RFC822, so we generate one our selfs.
+    use uuid::Uuid;
+    let boundary = format!("_Part_{}_", Uuid::new_v4().to_simple());
+    let alternative = MultiPart::alternative().boundary(boundary).singlepart(text).singlepart(html);
 
     let email = Message::builder()
         .to(Mailbox::new(None, Address::from_str(&address)?))
@@ -330,7 +318,7 @@ fn send_email(address: &str, subject: &str, body_html: &str, body_text: &str) ->
             Address::from_str(&CONFIG.smtp_from())?,
         ))
         .subject(subject)
-        .multipart(data)?;
+        .multipart(alternative)?;
 
     let _ = mailer().send(&email)?;
     Ok(())