Hacky node.js smtp server

smtp-server.js

// SMTP server in node.js (hacky)
var util = require('util');
var net = require('net');

/*
 * Template
=== Trying 127.0.0.1:25...
=== Connected to 127.0.0.1.
<-  220 Dexter ESMTP Exim 4.72 Mon, 22 Nov 2010 13:59:05 +0100
 -> EHLO Dexter
<-  250-Dexter Hello localhost [127.0.0.1]
<-  250-SIZE 52428800
<-  250-PIPELINING
<-  250 HELP
 -> MAIL FROM:<dxld@Dexter>
<-  250 OK
 -> RCPT TO:<[email protected]>
<-  250 Accepted
 -> DATA
<-  354 Enter message, ending with "." on a line by itself
 -> Date: Mon, 22 Nov 2010 13:59:05 +0100
 -> To: [email protected]
 -> From: dxld@Dexter
 -> Subject: test Mon, 22 Nov 2010 13:59:05 +0100
 -> X-Mailer: swaks v20100211.0 jetmore.org/john/code/swaks/
 -> 
 -> This is a test mailing
 -> 
 -> .
<-  250 OK id=1PKVz7-0001P8-CH
 -> QUIT
<-  221 Dexter closing connection
*/

var lineServer = function(accept){
    var server = net.createServer(function(stream){
        stream.on('data', function(data){
            var lines = data.toString().split('\r\n');
            lines.forEach(function(line, i){
                // not sure about that...
                if(!line){ return; }
                process.nextTick(function(){
                    stream.emit('line', line);
                });
            });
        });
        
        accept(stream);
    });
    return server;
}


var server = lineServer(function(stream){
    var state = {
        message: {
            from: ''
            , to: []
            , data: ''
            , in_transaction: false
        }
    };

    stream.setEncoding('utf-8');
    stream.on('connect', function(){
        stream.write('220 mail.haxxor.net SMTP Yo Mama\r\n');
    });

    stream.on('line', function(line){
        var cmd = line.substring(0, 4).toUpperCase();
        console.log('<-', line);

        if(state.message.in_transaction) {
            if(line == '.') {
                state.message.in_transaction = false;
                OK();
            }
            state.message.data += line + '\r\n';
        }

        if(cmd == 'EHLO') {
            MSG('250 ' + line);
        } else if(cmd == 'MAIL') {
            try {
                var addr = line.match(/MAIL FROM:<([^<>\r\n]*)>/)[1];
                state.message.from = addr;
                OK();
            } catch(e) {
                ERRO(e)
            }
        } else if(cmd == 'RCPT') {
            try {
                var addr = line.match(/RCPT TO:<([^<>\r\n]*)>/)[1];
                console.log('<** To:', addr);
                state.message.to.push(addr);
                OK();
            } catch(e) {
                ERRO(e);
            }
        } else if(cmd == 'DATA') {
            console.log(line);
            MSG('354 Start mail input; end with <CRLF>.<CRLF>');
            state.message.in_transaction = true;
        }

        else if(cmd == 'QUIT') {
            MSG('221 mail.haxxor.net Service closing transmission channel');
            stream.end();
        }
    });

    function MSG(msg){
        var buf = new Buffer(msg + '\r\n');
        console.log("-> " + buf.toString());
        stream.write(buf);
    }

    var _ok_buf = new Buffer('250 OK\r\n');
    function OK(){
        stream.write(_ok_buf);
    }

    function ERRO(e){
        throw e;
    }

});

server.listen(2525, '127.0.0.2');