Send bulk email

[ljfreelancer88]

Hi, I came from PHP background. What is the suggested way to send bulk email? I'm using the code below as an initial try.

use lettre::{
    transport::smtp::authentication::Credentials, 
    Message, 
    SmtpTransport, 
    Transport
};

fn main() {
    let message = Message::builder()
        .from("NoBody <info@dummy-domain.tld>".parse().unwrap())
        .reply_to("Admin <info@dummy-domain.tld>".parse().unwrap())
        .to("User <user@dummy-domain.tld>".parse().unwrap())
        .subject("Happy new year")
        .body(String::from("Be happy!"))
        .unwrap();

    let credentials = Credentials::new("username".to_string(), "password".to_string());

    let mailer = SmtpTransport::starttls_relay("smtp.mailtrap.io")
        .unwrap()
        .credentials(credentials)
        .build();

    // Send the email
    match mailer.send(&message) {
        Ok(_) => println!("Email sent successfully!"),
        Err(e) => panic!("Could not send email: {:?}", e),
    }
}

[paolobarbolini]

The question is very generic but one thing I'd suggest doing is reusing the mailer instance, even between threads, as it will mean recycling the same connections instead of having to reconnect back again everytime.

[ljfreelancer88]

This is what I have in mind, but I'm not sure if it's a good approach. I have checked the examples folder, but I have not found any.

users = [
{'id': 1, 'email': 'johndoe@domain.tld', 'name': 'John'},
{'id': 2, 'email': 'janedoe@domain.tld', 'name': 'Jane'}
];

loop(user from users)
    sendNotification(user)
    
fn sendNotification(user) {
    ...
   .to("user.name <user.email>".parse().unwrap())
} 

[IgnisDa]

@ljfreelancer88 Were you able to find a solution?

[IgnisDa]

@paolobarbolini Any solution to this? Sending the email in a loop works but I don't think is an ideal solution since my mail-server supports multiple receivers.