lemmy/lemmy_utils/src/email.rs

use crate::settings::Settings;
use lettre::{
  smtp::{
    authentication::{Credentials, Mechanism},
    extension::ClientId,
    ConnectionReuseParameters,
  },
  ClientSecurity,
  SmtpClient,
  Transport,
};
use lettre_email::Email;

pub fn send_email(
  subject: &str,
  to_email: &str,
  to_username: &str,
  html: &str,
) -> Result<(), String> {
  let email_config = Settings::get().email.ok_or("no_email_setup")?;

  let email = Email::builder()
    .to((to_email, to_username))
    .from(email_config.smtp_from_address.to_owned())
    .subject(subject)
    .html(html)
    .build()
    .unwrap();

  let mailer = if email_config.use_tls {
    SmtpClient::new_simple(&email_config.smtp_server).unwrap()
  } else {
    SmtpClient::new(&email_config.smtp_server, ClientSecurity::None).unwrap()
  }
  .hello_name(ClientId::Domain(Settings::get().hostname))
  .smtp_utf8(true)
  .authentication_mechanism(Mechanism::Plain)
  .connection_reuse(ConnectionReuseParameters::ReuseUnlimited);
  let mailer = if let (Some(login), Some(password)) =
    (&email_config.smtp_login, &email_config.smtp_password)
  {
    mailer.credentials(Credentials::new(login.to_owned(), password.to_owned()))
  } else {
    mailer
  };

  let mut transport = mailer.transport();
  let result = transport.send(email.into());
  transport.close();

  match result {
    Ok(_) => Ok(()),
    Err(e) => Err(e.to_string()),
  }
}