Q:

A simple local SMTP server

I want to test a Java code for sending email. I don't want to use any commercial mail client or connect to any external mail providers (like Gmail or Yahoo). I would like to know if there is any software which allows a user to configure dummy email addresses and server (locally) which can be used in my software to send and receive mails. I just want to test the functionality of the Java code.

A:

For email testing, try Dumbster. From their page:

The Dumbster is a very simple fake SMTP server designed for unit and
  system testing applications that send email messages. It responds to
  all standard SMTP commands but does not deliver messages to the user.
  The messages are stored within the Dumbster for later extraction and
  verification.
The Dumbster slots itself very easily into your testing strategy. As
  long as your application talks to an email server using SMTP then the
  Dumbster can be used to test the application with no code changes.

Various forks exist since the original page is no longer available:

https://github.com/kirviq/dumbster
https://github.com/rjo1970/dumbster

More can be found using a Github Search

A:

I prefer Fake SMTP for this. It's a desktop app (packed into jar file). Since it is written in Java, you can run it both from Linux/Mac/Windows

A:

You can use Wiser in the SubEthaSMTP library, Wiser's purpose is exactly what you want, unit testing.

