Crate mailin

A library for building smtp servers.

The library supplies a parser and SMTP state machine. The user of the library supplies I/O code and a Handler implementation for controlling SMTP sessions.

The code using the library, sends lines received to the Session.process_line() method. The user also supplies a Handler implementation that makes decisions on whether to accept or reject email messages. After consulting the Handler the Session.process_line() function will return a response that can be sent back to the email client.

Pseudo Code

// Create a handler which will control the SMTP session
let hander = create_handler();

// Create a SMTP session when a new client connects
let session = SessionBuilder::new("mailserver_name").build(client_ip, handler);

// Read a line from the client and strip the trailing /r/n
let line = read_line(tcp_connection);
// Send the line to the session
let res = session.process(line);

// Act on the response
match res.action {
    Action::Reply => {
        write_response(tcp_connection, &res)?;
    }
    Action::Close => {
        write_response(tcp_connection, &res)?;
        close(tcp_connection);
    }
    Action::NoReply => (), // No response needed
}

Structs

Response	Response contains a code and message to be sent back to the client
Session	A single smtp session connected to a single client
SessionBuilder	Builds an smtp Session

Enums

Action	Action indicates the recommended action to take on a response
AuthMechanism	Supported authentication mechanisms
AuthResult	AuthResult is the result of authenticating a smtp session
DataResult	DataResult is the result of an smtp DATA command
HeloResult	HeloResult is the result of an smtp HELO or EHLO command
MailResult	MailResult is the result of an smtp MAIL command
RcptResult	RcptResult is the result of an smtp RCPT command

Traits

Handler

A Handler makes decisions about incoming mail commands.