Add Content-Type to all examples sending a basic text/plain message (#859)

README.md

@@ -67,6 +67,7 @@ lettre = "0.10"
 ```
 
 ```rust,no_run
+use lettre::message::header::ContentType;
 use lettre::transport::smtp::authentication::Credentials;
 use lettre::{Message, SmtpTransport, Transport};
 
@@ -75,6 +76,7 @@ let email = Message::builder()
     .reply_to("Yuin <yuin@domain.tld>".parse().unwrap())
     .to("Hei <hei@domain.tld>".parse().unwrap())
     .subject("Happy new year")
+    .header(ContentType::TEXT_PLAIN)
     .body(String::from("Be happy!"))
     .unwrap();
 

examples/asyncstd1_smtp_starttls.rs

@@ -1,6 +1,6 @@
 use lettre::{
-    transport::smtp::authentication::Credentials, AsyncSmtpTransport, AsyncStd1Executor,
-    AsyncTransport, Message,
+    message::header::ContentType, transport::smtp::authentication::Credentials, AsyncSmtpTransport,
+    AsyncStd1Executor, AsyncTransport, Message,
 };
 
 #[async_std::main]
@@ -12,6 +12,7 @@ async fn main() {
         .reply_to("Yuin <yuin@domain.tld>".parse().unwrap())
         .to("Hei <hei@domain.tld>".parse().unwrap())
         .subject("Happy new async year")
+        .header(ContentType::TEXT_PLAIN)
         .body(String::from("Be happy with async!"))
         .unwrap();
 

examples/asyncstd1_smtp_tls.rs

@@ -1,6 +1,6 @@
 use lettre::{
-    transport::smtp::authentication::Credentials, AsyncSmtpTransport, AsyncStd1Executor,
-    AsyncTransport, Message,
+    message::header::ContentType, transport::smtp::authentication::Credentials, AsyncSmtpTransport,
+    AsyncStd1Executor, AsyncTransport, Message,
 };
 
 #[async_std::main]
@@ -12,6 +12,7 @@ async fn main() {
         .reply_to("Yuin <yuin@domain.tld>".parse().unwrap())
         .to("Hei <hei@domain.tld>".parse().unwrap())
         .subject("Happy new async year")
+        .header(ContentType::TEXT_PLAIN)
         .body(String::from("Be happy with async!"))
         .unwrap();
 

examples/smtp.rs

@@ -1,4 +1,4 @@
-use lettre::{Message, SmtpTransport, Transport};
+use lettre::{message::header::ContentType, Message, SmtpTransport, Transport};
 
 fn main() {
     tracing_subscriber::fmt::init();
@@ -8,6 +8,7 @@ fn main() {
         .reply_to("Yuin <yuin@domain.tld>".parse().unwrap())
         .to("Hei <hei@domain.tld>".parse().unwrap())
         .subject("Happy new year")
+        .header(ContentType::TEXT_PLAIN)
         .body(String::from("Be happy!"))
         .unwrap();
 

examples/smtp_selfsigned.rs

@@ -1,6 +1,7 @@
 use std::fs;
 
 use lettre::{
+    message::header::ContentType,
     transport::smtp::{
         authentication::Credentials,
         client::{Certificate, Tls, TlsParameters},
@@ -16,6 +17,7 @@ fn main() {
         .reply_to("Yuin <yuin@domain.tld>".parse().unwrap())
         .to("Hei <hei@domain.tld>".parse().unwrap())
         .subject("Happy new year")
+        .header(ContentType::TEXT_PLAIN)
         .body(String::from("Be happy!"))
         .unwrap();
 

examples/smtp_starttls.rs

@@ -1,4 +1,7 @@
-use lettre::{transport::smtp::authentication::Credentials, Message, SmtpTransport, Transport};
+use lettre::{
+    message::header::ContentType, transport::smtp::authentication::Credentials, Message,
+    SmtpTransport, Transport,
+};
 
 fn main() {
     tracing_subscriber::fmt::init();
@@ -8,6 +11,7 @@ fn main() {
         .reply_to("Yuin <yuin@domain.tld>".parse().unwrap())
         .to("Hei <hei@domain.tld>".parse().unwrap())
         .subject("Happy new year")
+        .header(ContentType::TEXT_PLAIN)
         .body(String::from("Be happy!"))
         .unwrap();
 

examples/smtp_tls.rs

@@ -1,4 +1,7 @@
-use lettre::{transport::smtp::authentication::Credentials, Message, SmtpTransport, Transport};
+use lettre::{
+    message::header::ContentType, transport::smtp::authentication::Credentials, Message,
+    SmtpTransport, Transport,
+};
 
 fn main() {
     tracing_subscriber::fmt::init();
@@ -8,6 +11,7 @@ fn main() {
         .reply_to("Yuin <yuin@domain.tld>".parse().unwrap())
         .to("Hei <hei@domain.tld>".parse().unwrap())
         .subject("Happy new year")
+        .header(ContentType::TEXT_PLAIN)
         .body(String::from("Be happy!"))
         .unwrap();
 

examples/tokio1_smtp_starttls.rs

@@ -2,8 +2,8 @@
 // since it uses Rust 2018 crate renaming to import tokio.
 // Won't be needed in user's code.
 use lettre::{
-    transport::smtp::authentication::Credentials, AsyncSmtpTransport, AsyncTransport, Message,
-    Tokio1Executor,
+    message::header::ContentType, transport::smtp::authentication::Credentials, AsyncSmtpTransport,
+    AsyncTransport, Message, Tokio1Executor,
 };
 use tokio1_crate as tokio;
 
@@ -16,6 +16,7 @@ async fn main() {
         .reply_to("Yuin <yuin@domain.tld>".parse().unwrap())
         .to("Hei <hei@domain.tld>".parse().unwrap())
         .subject("Happy new async year")
+        .header(ContentType::TEXT_PLAIN)
         .body(String::from("Be happy with async!"))
         .unwrap();
 

examples/tokio1_smtp_tls.rs

@@ -2,8 +2,8 @@
 // since it uses Rust 2018 crate renaming to import tokio.
 // Won't be needed in user's code.
 use lettre::{
-    transport::smtp::authentication::Credentials, AsyncSmtpTransport, AsyncTransport, Message,
-    Tokio1Executor,
+    message::header::ContentType, transport::smtp::authentication::Credentials, AsyncSmtpTransport,
+    AsyncTransport, Message, Tokio1Executor,
 };
 use tokio1_crate as tokio;
 
@@ -16,6 +16,7 @@ async fn main() {
         .reply_to("Yuin <yuin@domain.tld>".parse().unwrap())
         .to("Hei <hei@domain.tld>".parse().unwrap())
         .subject("Happy new async year")
+        .header(ContentType::TEXT_PLAIN)
         .body(String::from("Be happy with async!"))
         .unwrap();