Added: STARTTLS example

examples/starttls.rs

@@ -0,0 +1,68 @@
+/**
+ * Here's an example showing how to connect to the IMAP server with STARTTLS.
+ * The only difference with the `basic.rs` example is when using `imap::connect_starttls()` method
+ * instead of `imap::connect()` (l. 52)
+ *
+ * The following env vars are expected to be set:
+ * - IMAP_HOST
+ * - IMAP_USERNAME
+ * - IMAP_PASSWORD
+ * - IMAP_PORT (supposed to be 143)
+ */
+
+extern crate imap;
+extern crate native_tls;
+
+use native_tls::TlsConnector;
+use std::env;
+use std::error::Error;
+
+fn main() -> Result<(), Box<dyn Error>> {
+    let imap_host = env::var("IMAP_HOST")
+        .expect("Missing or invalid env var: IMAP_HOST");
+    let imap_username = env::var("IMAP_USERNAME")
+        .expect("Missing or invalid env var: IMAP_USERNAME");
+    let imap_password = env::var("IMAP_PASSWORD")
+        .expect("Missing or invalid env var: IMAP_PASSWORD");
+    let imap_port: u16 = env::var("IMAP_PORT")
+        .expect("Missing or invalid env var: IMAP_PORT")
+        .to_string()
+        .parse()
+        .unwrap();
+
+    if let Some(_email) = fetch_inbox_top(imap_host, imap_username, imap_password, imap_port)? {
+        eprintln!("OK :)");
+    }
+
+    Ok(())
+}
+
+fn fetch_inbox_top(
+    host: String,
+    username: String,
+    password: String,
+    port: u16,
+) -> Result<Option<String>, Box<dyn Error>> {
+    let domain: &str = host.as_str();
+
+    let tls = TlsConnector::builder().build().unwrap();
+
+    // we pass in the domain twice to check that the server's TLS
+    // certificate is valid for the domain we're connecting to.
+    let client = imap::connect_starttls(
+        (domain, port),
+        domain,
+        &tls,
+    ).unwrap();
+
+    // the client we have here is unauthenticated.
+    // to do anything useful with the e-mails, we need to log in
+    let mut _imap_session = client
+        .login(username.as_str(), password.as_str())
+        .map_err(|e| e.0)?;
+
+    // TODO Here you can process as you want. eg. search/fetch messages according to your needs.
+
+    // This returns `Ok(None)` for the need of the example
+    Ok(None)
+}