feat(all): Merge lettre_email into lettre with a builder feature

examples/smtp.rs

@@ -0,0 +1,31 @@
+extern crate env_logger;
+extern crate lettre;
+
+use lettre::{EmailAddress, Envelope, SendableEmail, SmtpClient, Transport};
+
+fn main() {
+    env_logger::init();
+
+    let email = SendableEmail::new(
+        Envelope::new(
+            Some(EmailAddress::new("user@localhost".to_string()).unwrap()),
+            vec![EmailAddress::new("root@localhost".to_string()).unwrap()],
+        )
+        .unwrap(),
+        "id".to_string(),
+        "Hello ß☺ example".to_string().into_bytes(),
+    );
+
+    // Open a local connection on port 25
+    let mut mailer = SmtpClient::new_unencrypted_localhost().unwrap().transport();
+    // Send the email
+    let result = mailer.send(email);
+
+    if result.is_ok() {
+        println!("Email sent");
+    } else {
+        println!("Could not send email: {:?}", result);
+    }
+
+    assert!(result.is_ok());
+}