Crate rusmes_smtp 

SMTP protocol implementation for RusMES

This crate provides a full-featured, RFC 5321-compliant SMTP server implementation built on Tokio for asynchronous I/O.

Features

• RFC 5321 Compliance: Complete SMTP protocol including HELO/EHLO, MAIL FROM, RCPT TO, DATA, QUIT, RSET, NOOP, and VRFY.
• STARTTLS (RFC 3207): Opportunistic TLS upgrade for secure transport.
• AUTH (RFC 4954): Multiple SASL mechanisms:
  • PLAIN (RFC 4616)
  • LOGIN
  • CRAM-MD5 (RFC 2195)
  • SCRAM-SHA-256 (RFC 5802 / RFC 7677)
• PIPELINING (RFC 2920): Client-side pipelining support.
• DSN (RFC 3461): Delivery Status Notification extensions.
• CHUNKING / BDAT (RFC 3030): Binary data transfer without dot-stuffing.
• SIZE (RFC 1870): Message size declaration.
• 8BITMIME (RFC 6152): 8-bit MIME content transfer.
• SMTPUTF8 (RFC 6531): Unicode email addresses.
• Submission (RFC 4409 / RFC 6409): MSA mode on port 587.

Modules

• auth: SASL authentication mechanism implementations.
• bdat: BDAT/CHUNKING extension state machine (RFC 3030).
• command: SMTP command types and parameters.
• dsn: Delivery Status Notification parameter parsing (RFC 3461).
• parser: Nom-based SMTP command parser.
• response: SMTP response code formatting.
• server: Async TCP listener and connection acceptor.
• session: Per-connection state machine and command dispatcher.
• submission: Mail Submission Agent (MSA) server variant.

Quick Start

use std::sync::Arc;
use rusmes_smtp::{SmtpConfig, SmtpServer};

#[tokio::main]
async fn main() -> anyhow::Result<()> {
    let config = SmtpConfig {
        hostname: "mail.example.com".to_string(),
        max_message_size: 10 * 1024 * 1024, // 10 MiB
        require_auth: false,
        enable_starttls: false,
        ..Default::default()
    };
    // Build and run the server (requires auth/storage backends)
    // let server = SmtpServer::new(config, auth_backend, storage_backend);
    // server.listen("0.0.0.0:25").await?;
    Ok(())
}

Re-exports

pub use bdat::BdatCommand;

pub use bdat::BdatError;

pub use bdat::BdatState;

pub use command::MailParam;

pub use command::SmtpCommand;

pub use dsn::DsnError;

pub use dsn::DsnMailParams;

pub use dsn::DsnNotify;

pub use dsn::DsnRcptParams;

pub use dsn::DsnRet;

pub use parser::parse_command;

pub use response::SmtpResponse;

pub use server::SmtpServer;

pub use session::SmtpConfig;

pub use session::SmtpSession;

pub use session::SmtpSessionHandler;

pub use session::SmtpState;

pub use submission::SubmissionConfig;

pub use submission::SubmissionServer;

Modules

auth

SMTP authentication mechanisms

bdat

SMTP CHUNKING/BDAT Extension - RFC 3030

command

SMTP command types

dsn

SMTP DSN (Delivery Status Notification) Extension - RFC 3461

parser

SMTP command parser using nom

response

SMTP response types and codes

server

SMTP server implementation

session

SMTP session state machine and handler

submission

SMTP Submission Server (RFC 6409) - Port 587

Functions

is_ip_in_networks

Check if an IP address is in any of the given CIDR networks