Too many unauthenticated commands while authOptional is true

[jaspervann]

The following line should check for this._server.options.authOptional, because if authOptional option is set to true, there may be infinite unauthenticated commands:

smtp-server/lib/smtp-connection.js

Line 454 in 17fd809

if (!this.session.user && this._isSupported('AUTH') && commandName !== 'AUTH' && this._maxAllowedUnauthenticatedCommands !== false) {

Currently even whilst you set authOptional to true, the server will throw a "421 - Error: too many unauthenticated commands" after receiving _maxAllowedUnauthenticatedCommands unauthenticated commands. That's not desirable, because authentication in this case was not required.

[jaspervann]

The solution to issue #161 also resolves this problem.