by Howard Miller.
Your question doesn't really make sense to me. I assume you are actually asking how to "test" email-based authentication?
If you want to test something that involves emails being sent and you have no internet connection then you can't do it. Well, you could use 'local' email but, as I suspect you are using Windows, this won't be straightforward (it's easy-ish on Linux).
Anyway - you don't need to test it, it's been tested, it works.
However, I suspect I am missing something...