use mail_builder::MessageBuilder;
fn main() {
let eml = MessageBuilder::new()
.from(("John Doe", "john@doe.com"))
.to("jane@doe.com")
.subject("Hello, world!")
.text_body("Message contents go here.")
.attachment("image/png", "image.png", [1, 2, 3, 4].as_ref())
.write_to_string()
.unwrap();
println!("{}", eml);
}