Spamm3r is a project mainly written in C#, it's free.
An epic email spammer :]
The spamm3r is a simple application that lets you send emails to anyone, from an email adress and name you provide.
This is an open source project, so if you would like to edit it, make your own changes just download everything here and open it up in your Visual Studio, just make sure you give credit to tw0n if you make changes and release it. Or if you have an account here, fork it!
YOU NEED .NET 4.0 TO RUN THIS PROGRAM :D --> http://is.gd/asWM1s
Updates are constantly being released, so be sure to check back here every few days to see if there's a new one. The message of the 'source' folder will relate to the current version. So if the version displayed in your application is different than what is displayed in the message here, it's time to update.
To update, click the downloads button, then click tw0n spamm3r v1.x.xx.exe - that will always be the up to date version and is a lot easier if you just want the application and not the source code.
I'm always trying to find a better, more reliable SMTP host to provide you with less emails getting thrown to junk boxes and faster sending times, etc. A few things I have on my to-do list are:
Import a .txt file with emails (1 per line) to send to
A nice and pretty interface
A bomber