Consider adding mode to test error handling

[nbaksalyar]

It would be nice if GreenMail had an option to explicitly define error responses to test error handling in user's code.

For example check MailHog, a fake SMTP server. It has a special mode to randomly reject connections, authentications, etc.

Another good example is Netflix's Chaos Monkey that is used to test distributed systems.

[marcelmay]

Thanks for the input.

We have something like this planned in #40 - where you can define event rules.
Do you have any concrete error cases in mind?

[nbaksalyar]

Do you have any concrete error cases in mind?

I guess cases available in MailHog would be a good start:

1. Reject connections (a socket exception);
2. Reject authentication;
3. Reject recipients (SMTPAddressFailedException);
4. Reject senders (SMTPSenderFailedException).

These should cover most of the basic SMTP errors.
I'm not sure about IMAP, though.