Apache James as mail server.
It seems the project is useful however there are really limited resources.
The example on the link below somehow worked and I am able to use it;
https://javaworld-abhinav.blogspot.com/2019/04/setting-up-local-mail-server-using.html
Looking for more example and tutorials.
As I find the resources, I will be editing here.
The video is really a good motivation to use James as a mail server because there is completed reference project
hi_rullah 