new file: backend/examples/crabfeeder.rs

README.md

@@ -109,6 +109,16 @@ services:
     networks: [default]
 ```
 
+## Sample messages
+
+The `samples` directory contains a couple of test messages.
+These can be sent using by running:
+
+```sh
+cd backend/
+cargo run --example crabfeeder ../samples/*l
+```
+
 ## Development
 
 Install [Rust](https://www.rust-lang.org/learn/get-started) and [Trunk](https://trunkrs.dev/)

backend/examples/crabfeeder.rs

@@ -0,0 +1,65 @@
+/*
+ * crabfeeder
+ * a SMTP client
+ * for injecting (test) emails into mailcrab
+ */
+use core::str::FromStr;
+use lettre::address::Envelope;
+use lettre::{Address, SmtpTransport, Transport};
+use std::env;
+use std::net::IpAddr;
+
+fn usage(name: &str) {
+    println!(
+        r#"{name} <filenames>
+
+and those filenames will be injected as email into mailcrab.
+
+You can configure the connection destination with setting
+environment variables SMTP_SERVER and SMTP_PORT.
+"#
+    )
+}
+
+fn main() {
+    let args: Vec<String> = env::args().collect();
+    if args.len() > 1 {
+        process(args[1..].to_vec());
+    } else {
+        usage(&args[0]);
+    }
+}
+
+/// get a configuration from the environment or return default value
+fn parse_env_var<T: FromStr>(name: &'static str, default: T) -> T {
+    env::var(name)
+        .unwrap_or_default()
+        .parse::<T>()
+        .unwrap_or(default)
+}
+
+fn process(filenames: Vec<String>) {
+    let smtp_server: IpAddr = parse_env_var("SMTP_SERVER", [127, 0, 0, 1].into());
+    let smtp_port: u16 = parse_env_var("SMTP_PORT", 1025);
+    println!("I: Will connecting {:?}:{:?}", smtp_server, smtp_port);
+    let mailer = SmtpTransport::builder_dangerous(smtp_server.to_string())
+        .port(smtp_port)
+        .build();
+
+    for f in filenames.iter() {
+        let message = std::fs::read_to_string(f).unwrap();
+        let lines = message.lines();
+
+        let sender = "carbfeeder@carbfeeder".parse::<Address>().unwrap();
+        let recipients = "mailcrab@mailcrab"
+            .split(',')
+            .map(|r| r.trim().parse::<Address>().unwrap())
+            .collect::<Vec<Address>>();
+        let envelope = Envelope::new(Some(sender), recipients).unwrap();
+
+        let email = lines.collect::<Vec<&str>>().join("\n");
+
+        mailer.send_raw(&envelope, email.as_bytes()).unwrap();
+        println!("I: Having send {f}");
+    }
+}

backend/examples/multiple_rcpt_to.rs

@@ -0,0 +1,53 @@
+/*
+ * multiple_rcpt_to
+ * a SMTP client
+ * that injects a (test) email into mailcrab
+ * for multiple recipients
+ */
+use core::str::FromStr;
+use lettre::address::Envelope;
+use lettre::{Address, SmtpTransport, Transport};
+use std::env;
+use std::net::IpAddr;
+
+/// get a configuration from the environment or return default value
+fn parse_env_var<T: FromStr>(name: &'static str, default: T) -> T {
+    env::var(name)
+        .unwrap_or_default()
+        .parse::<T>()
+        .unwrap_or(default)
+}
+
+fn main() {
+    let smtp_server: IpAddr = parse_env_var("SMTP_SERVER", [127, 0, 0, 1].into());
+    let smtp_port: u16 = parse_env_var("SMTP_PORT", 1025);
+    println!("I: Will connecting {:?}:{:?}", smtp_server, smtp_port);
+    let mailer = SmtpTransport::builder_dangerous(smtp_server.to_string())
+        .port(smtp_port)
+        .build();
+
+    let sender = "multi_rcpt_to@examples".parse::<Address>().unwrap();
+    let recipients = "many@mailcrab,foo@bar,foo@baz,[email protected],[email protected]"
+        .split(',')
+        .map(|r| r.trim().parse::<Address>().unwrap())
+        .collect::<Vec<Address>>();
+    let envelope = Envelope::new(Some(sender), recipients).unwrap();
+
+    let email = r#"From: Many RCPT TO <recipient@metadata>
+To: See Envelope <[email protected]>
+Subject: Multiple RCPT TO in one SMTP session
+
+Hi,
+
+This message is for checking
+how mailcrab handles multiple RCPT TO in one SMTP session.
+
+Inspirated by the commit you can see with
+  git log --patch 0699315cb2509^1..0699315cb2509
+
+Bye
+"#;
+
+    mailer.send_raw(&envelope, email.as_bytes()).unwrap();
+    println!("I: Having send one email");
+}