[−][src]Module lettre::transport::smtp
smtp-transport
only.The SMTP transport sends emails using the SMTP protocol.
This SMTP client follows RFC 5321, and is designed to efficiently send emails from an application to a relay email server, as it relies as much as possible on the relay server for sanity and RFC compliance checks.
It implements the following extensions:
SMTP Transport
This transport uses the SMTP protocol to send emails over the network (locally or remotely).
It is designed to be:
- Secured: connections are encrypted by default
- Modern: unicode support for email contents and sender/recipient addresses when compatible
- Fast: supports connection reuse and pooling
This client is designed to send emails to a relay server, and should not be used to send emails directly to the destination server.
The relay server can be the local email server, a specific host or a third-party service.
Simple example
This is the most basic example of usage:
use lettre::{Message, Transport, SmtpTransport}; let email = Message::builder() .from("NoBody <nobody@domain.tld>".parse()?) .reply_to("Yuin <yuin@domain.tld>".parse()?) .to("Hei <hei@domain.tld>".parse()?) .subject("Happy new year") .body(String::from("Be happy!"))?; // Create TLS transport on port 465 let sender = SmtpTransport::relay("smtp.example.com") .expect("relay valid") .build(); // Send the email via remote relay let result = sender.send(&email); assert!(result.is_ok());
Complete example
# #[cfg(feature = "smtp-transport")]
# {
use lettre::transport::smtp::authentication::{Credentials, Mechanism};
use lettre::{Email, Envelope, Transport, SmtpClient};
use lettre::transport::smtp::extension::ClientId;
let email_1 = Email::new(
Envelope::new(
Some(EmailAddress::new("user@localhost".to_string())?),
vec![EmailAddress::new("root@localhost".to_string())?],
)?,
"id1".to_string(),
"Hello world".to_string().into_bytes(),
);
let email_2 = Email::new(
Envelope::new(
Some(EmailAddress::new("user@localhost".to_string())?),
vec![EmailAddress::new("root@localhost".to_string())?],
)?,
"id2".to_string(),
"Hello world a second time".to_string().into_bytes(),
);
// Connect to a remote server on a custom port
let mut mailer = SmtpClient::new_simple("server.tld")?
// Set the name sent during EHLO/HELO, default is `localhost`
.hello_name(ClientId::Domain("my.hostname.tld".to_string()))
// Add credentials for authentication
.credentials(Credentials::new("username".to_string(), "password".to_string()))
// Enable SMTPUTF8 if the server supports it
.smtp_utf8(true)
// Configure expected authentication mechanism
.authentication_mechanism(Mechanism::Plain)
// Enable connection reuse
.connection_reuse(ConnectionReuseParameters::ReuseUnlimited).transport();
let result_1 = mailer.send(&email_1);
assert!(result_1.is_ok());
// The second email will use the same connection
let result_2 = mailer.send(&email_2);
assert!(result_2.is_ok());
// Explicitly close the SMTP transaction as we enabled connection reuse
mailer.close();
# }
You can specify custom TLS settings:
# #[cfg(feature = "native-tls")]
# {
use lettre::{
ClientSecurity, ClientTlsParameters, EmailAddress, Envelope,
Email, SmtpClient, Transport,
};
use lettre::transport::smtp::authentication::{Credentials, Mechanism};
use lettre::transport::smtp::ConnectionReuseParameters;
use native_tls::{Protocol, TlsConnector};
let email = Email::new(
Envelope::new(
Some(EmailAddress::new("user@localhost".to_string())?),
vec![EmailAddress::new("root@localhost".to_string())?],
)?,
"message_id".to_string(),
"Hello world".to_string().into_bytes(),
);
let mut tls_builder = TlsConnector::builder();
tls_builder.min_protocol_version(Some(Protocol::Tlsv10));
let tls_parameters =
ClientTlsParameters::new(
"smtp.example.com".to_string(),
tls_builder.build()?
);
let mut mailer = SmtpClient::new(
("smtp.example.com", 465), ClientSecurity::Wrapper(tls_parameters)
)?
.authentication_mechanism(Mechanism::Login)
.credentials(Credentials::new(
"example_username".to_string(), "example_password".to_string()
))
.connection_reuse(ConnectionReuseParameters::ReuseUnlimited)
.transport();
let result = mailer.send(&email);
assert!(result.is_ok());
mailer.close();
# }
Modules
authentication | Provides limited SASL authentication mechanisms |
client | SMTP client |
commands | SMTP commands |
extension | ESMTP features |
response | SMTP response, containing a mandatory return code and an optional text message |
util | Utils for string manipulation |
Structs
AsyncSmtpTransport | |
AsyncSmtpTransportBuilder | Contains client configuration.
Instances of this struct can be created using functions of |
AsyncStd1Connector | async-std1 |
PoolConfig | r2d2 Configuration for a connection pool |
SmtpTransport | |
SmtpTransportBuilder | Contains client configuration.
Instances of this struct can be created using functions of |
Tokio1Connector | tokio1 |
Tokio02Connector | tokio02 |
Enums
Error | An enum of all error kinds. |
Constants
DEFAULT_TIMEOUT | Default timeout |
SMTP_PORT | Default smtp port |
SUBMISSIONS_PORT | Default submission over TLS port |
SUBMISSION_PORT | Default submission port |
Traits
AsyncSmtpConnector |