zonemta authentication

authplugin.toml

# store to config/plugins/authplugin.toml
[authplugin]
enabled="receiver"

autphlugin.js

// store to plugins/authplugin.js

'use strict';

const username = 'user';
const password = 'secret';

module.exports.title = 'Simple Authentication';
module.exports.init = function(app, done) {
    // Listen for AUTH command
    app.addHook('smtp:auth', (auth, session, next) => {
        if (auth.username !== username || auth.password !== password) {
            // authentication failed
            let err = new Error('Authentication failed');
            err.responseCode = 535;
            return next(err);
        }
        // consider the authentication as succeeded as we did not get an error
        next();
    });

    done();
};

autphlugin.js is a typo - it should be authplugin.js - Unfortunately, I can't seem to get the authentication working. @andris9