You can find the code here: https://github.com/manuel_mauky/tmpmail
Task: Temporal email addresses
The user of the application should be able to register herself with her private email address. After that the user can create temporal email addresses whose messages are redirected to the private email address of the user.
There are several use cases for this application: First of all you can use this temporal email addresses for registration at online shops, forums and so on where you don't want to use your private email address to prevent spam emails.
Another use case would be to use this application for testing purposes by software developers. They could check whether there own application is sending emails the correct way.
The handling of SMTP is done with the SubethaSMTP library.
p.s. At the end I won the contest and got a Lenovo Thinkpad Edge as an award :-)